Reservoir and heater system for controllable delivery of multiple aerosolizable materials in an electronic smoking article

ABSTRACT

The present disclosure relates to an electronic smoking article that provides for improved aerosol delivery. Particularly, the article provides for separate delivery of two or more components of an aerosol precursor composition to one or more heaters so as to control the rate of delivery or the rate of heating of the separate components of the aerosol precursor composition.

FIELD OF THE INVENTION

The present invention relates to aerosol delivery articles and usesthereof for yielding tobacco components or other materials in aninhalable form. The articles can be made or derived from tobacco orotherwise incorporate tobacco for human consumption.

BACKGROUND OF THE INVENTION

Many smoking articles have been proposed through the years asimprovements upon, or alternatives to, smoking products based uponcombusting tobacco. Exemplary alternatives have included devices whereina solid or liquid fuel is combusted to transfer heat to tobacco orwherein a chemical reaction is used to provide such heat source.Numerous references have proposed various smoking articles of a typethat generate flavored vapor, visible aerosol, or a mixture of flavoredvapor and visible aerosol. Some of those proposed types of smokingarticles include tubular sections or longitudinally extending airpassageways.

The point of the improvements or alternatives to smoking articlestypically has been to provide the sensations associated with cigarette,cigar, or pipe smoking, without delivering considerable quantities ofincomplete combustion and pyrolysis products. To this end, there havebeen proposed numerous smoking products, flavor generators, andmedicinal inhalers which utilize electrical energy to vaporize or heat avolatile material, or attempt to provide the sensations of cigarette,cigar, or pipe smoking without burning tobacco.

General examples of alternative smoking articles are described in U.S.Pat. No. 3,258,015 to Ellis et al.; U.S. Pat. No. 3,356,094 to Ellis etal.; U.S. Pat. No. 3,516,417 to Moses; U.S. Pat. No. 4,347,855 toLanzellotti et al.; U.S. Pat. No. 4,340,072 to Bolt et al.; U.S. Pat.No. 4,391,285 to Burnett et al.; U.S. Pat. No. 4,917,121 to Riehl etal.; U.S. Pat. No. 4,924,886 to Litzinger; and U.S. Pat. No. 5,060,676to Hearn et al. Many of those types of smoking articles have employed acombustible fuel source that is burned to provide an aerosol and/or toheat an aerosol-forming material. See, for example, the background artcited in U.S. Pat. No. 4,714,082 to Banerjee et al. and U.S. Pat. No.4,771,795 to White et al.; which are incorporated herein by reference intheir entireties. See, also, for example, those types of smokingarticles described in U.S. Pat. No. 4,756,318 to Clearman et al.; U.S.Pat. No. 4,714,082 to Banerjee et al.; U.S. Pat. No. 4,771,795 to Whiteet al.; U.S. Pat. No. 4,793,365 to Sensabaugh et al.; U.S. Pat. No.4,917,128 to Clearman et al.; U.S. Pat. No. 4,961,438 to Korte; U.S.Pat. No. 4,966,171 to Serrano et al.; U.S. Pat. No. 4,969,476 to Bale etal.; U.S. Pat. No. 4,991,606 to Serrano et al.; U.S. Pat. No. 5,020,548to Farrier et al.; U.S. Pat. No. 5,033,483 to Clearman et al.; U.S. Pat.No. 5,040,551 to Schlatter et al.; U.S. Pat. No. 5,050,621 to Creightonet al.; U.S. Pat. No. 5,065,776 to Lawson; U.S. Pat. No. 5,076,296 toNystrom et al.; U.S. Pat. No. 5,076,297 to Farrier et al.; U.S. Pat. No.5,099,861 to Clearman et al.; U.S. Pat. No. 5,105,835 to Drewett et al.;U.S. Pat. No. 5,105,837 to Barnes et al.; U.S. Pat. No. 5,115,820 toHauser et al.; U.S. Pat. No. 5,148,821 to Best et al.; U.S. Pat. No.5,159,940 to Hayward et al.; U.S. Pat. No. 5,178,167 to Riggs et al.;U.S. Pat. No. 5,183,062 to Clearman et al.; U.S. Pat. No. 5,211,684 toShannon et al.; U.S. Pat. No. 5,240,014 to Deevi et al.; U.S. Pat. No.5,240,016 to Nichols et al.; U.S. Pat. No. 5,345,955 to Clearman et al.;U.S. Pat. No. 5,551,451 to Riggs et al.; U.S. Pat. No. 5,595,577 toBensalem et al.; U.S. Pat. No. 5,819,751 to Barnes et al.; U.S. Pat. No.6,089,857 to Matsuura et al.; U.S. Pat. No. 6,095,152 to Beven et al;U.S. Pat. No. 6,578,584 Beven; and U.S. Pat. No. 6,730,832 to Dominguez;which are incorporated herein by reference in their entireties.Furthermore, certain types of cigarettes that employ carbonaceous fuelelements have been commercially marketed under the brand names “Premier”and “Eclipse” by R. J. Reynolds Tobacco Company. See, for example, thosetypes of cigarettes described in Chemical and Biological Studies on NewCigarette Prototypes that Heat Instead of Burn Tobacco, R. J. ReynoldsTobacco Company Monograph (1988) and Inhalation Toxicology, 12:5, p.1-58 (2000). See also US Pat. Pub. No. 2005/0274390 to Banerjee et al.,US Pat. Pub. No. 2007/0215167 to Crooks et al., US Pat. Pub. No.2010/0065075 to Banerjee et al., and US Pat. Pub. No. 2012/0042885 toStone et al., the disclosures of which are incorporated herein byreference in their entireties.

Certain proposed cigarette-shaped tobacco products purportedly employtobacco in a form that is not intended to be burned to any significantdegree. See, for example, U.S. Pat. No. 4,836,225 to Sudoh; U.S. Pat.No. 4,972,855 to Kuriyama et al.; and U.S. Pat. No. 5,293,883 toEdwards, which are incorporated herein by reference in their entireties.Yet other types of smoking articles, such as those types of smokingarticles that generate flavored vapors by subjecting tobacco orprocessed tobaccos to heat produced from chemical or electrical heatsources, are described in U.S. Pat. No. 4,848,374 to Chard et al.; U.S.Pat. Nos. 4,947,874 and 4,947,875 to Brooks et al.; U.S. Pat. No.5,060,671 to Counts et al.; U.S. Pat. No. 5,146,934 to Deevi et al.;U.S. Pat. No. 5,224,498 to Deevi; U.S. Pat. No. 5,285,798 to Banerjee etal.; U.S. Pat. No. 5,357,984 to Farrier et al.; U.S. Pat. No. 5,593,792to Farrier et al.; U.S. Pat. No. 5,369,723 to Counts; U.S. Pat. No.5,692,525 to Counts et al.; U.S. Pat. No. 5,865,185 to Collins et al.;U.S. Pat. No. 5,878,752 to Adams et al.; U.S. Pat. No. 5,880,439 toDeevi et al.; U.S. Pat. No. 5,915,387 to Baggett et al.; U.S. Pat. No.5,934,289 to Watkins et al.; U.S. Pat. No. 6,033,623 to Deevi et al.;U.S. Pat. No. 6,053,176 to Adams et al.; U.S. Pat. No. 6,164,287 toWhite; U.S. Pat. No. 6,289,898 to Fournier et al.; U.S. Pat. No.6,615,840 to Fournier et al.; U.S. Pat. Pub. No. 2003/0131859 to Li etal.; U.S. Pat. Pub. No. 2005/0016549 to Banerjee et al.; and U.S. Pat.Pub. No. 2006/0185687 to Hearn et al., each of which is incorporatedherein by reference in its entirety.

Certain attempts have been made to deliver vapors, sprays or aerosols,such as those possessing or incorporating flavors and/or nicotine. See,for example, the types of devices set forth in U.S. Pat. No. 4,190,046to Virag; U.S. Pat. No. 4,284,089 to Ray; U.S. Pat. No. 4,635,651 toJacobs; U.S. Pat. No. 4,735,217 to Gerth et al.; U.S. Pat. No. 4,800,903to Ray et al.; U.S. Pat. No. 5,388,574 to Ingebrethsen et al.; U.S. Pat.No. 5,799,663 to Gross et al.; U.S. Pat. No. 6,532,965 to Abhulimen etal.; and U.S. Pat. No. 6,598,607 to Adiga et al; and EP 1,618,803 toHon; which are incorporated herein by reference in their entireties. Seealso, U.S. Pat. No. 7,117,867 to Cox et al. and the devices set forth onthe website, www.e-cig.com, which are incorporated herein by referencein their entireties.

Still further representative cigarettes or smoking articles that havebeen described and, in some instances, been made commercially availableinclude those described in U.S. Pat. No. 4,922,901 to Brooks et al.;U.S. Pat. No. 5,249,586 to Morgan et al.; U.S. Pat. No. 5,388,594 toCounts et al.; U.S. Pat. No. 5,666,977 to Higgins et al.; U.S. Pat. No.6,196,218 to Voges; U.S. Pat. No. 6,810,883 to Felter et al.; U.S. Pat.No. 6,854,461 to Nichols; U.S. Pat. No. 7,832,410 to Hon; U.S. Pat. No.7,513,253 to Kobayashi; U.S. Pat. No. 7,726,320 to Robinson et al.; U.S.Pat. No. 7,896,006 to Hamano; U.S. Pat. No. 6,772,756 to Shayan; US Pat.Pub. No. 2009/0095311 to Hon; US Pat. Pub. Nos. 2006/0196518,2009/0126745, and 2009/0188490 to Hon; US Pat. Pub. No. 2009/0272379 toThorens et al.; US Pat. Pub. Nos. 2009/0260641 and 2009/0260642 toMonsees et al.; US Pat. Pub. Nos. 2008/0149118 and 2010/0024834 toOglesby et al.; US Pat. Pub. No. 2010/0307518 to Wang; and WO2010/091593 to Hon. See also U.S. Pat. No. D657,047 to Minskoff et al.and US Pat. Pub. Nos. 2011/0277757, 2011/0277760, and US 2011/0277764 toTerry et al. Still further examples include electronic cigaretteproducts commercially available under the names ACCORD®; HEATBAR™;HYBRID CIGARETTE®, VEGAS™; E-GAR™; C-GAR™; E-MYSTICK™; IOLITE®Vaporizer, GREEN SMOKE®, BLU™ Cigs, WHITE CLOUD® Cirrus, V2CIGS™, SOUTHBEACH SMOKE™, SMOKETIP®, SMOKE STIK®, NJOY®, LUCI®, Royal Blues, SMARTSMOKER®, SMOKE ASSIST®, Knight Sticks, GAMUCCI®, InnoVapor, SMOKINGEVERYWHERE®, Crown 7, CHOICE™ NO.7™, VAPORKING®, EPUFFER®, LOGIC™ ecig,VAPOR4LIFE®, NICOTEK®, METRO®, and PREMIUM™.

Smoking articles that employ tobacco substitute materials and smokingarticles that employ sources of heat other than burning tobacco cutfiller to produce tobacco-flavored vapors or tobacco-flavored visibleaerosols have not received widespread commercial success. Articles thatproduce the taste and sensation of smoking by electrically heatingtobacco particularly have suffered from inconsistent release of flavorsor other inhalable materials. Electrically heated smoking devices havefurther been limited in many instances to the requirement of an externalheating device that was inconvenient and that detracted from the smokingexperience. Accordingly, it can be desirable to provide a smokingarticle that can provide the sensations of cigarette, cigar, or pipesmoking, that does so without combusting tobacco, that does so withoutthe need of a combustion heat source, and that does so withoutnecessarily delivering considerable quantities of incomplete combustionand pyrolysis products.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a smoking article and methods of usethereof for controllably delivering aerosol precursor components. Inparticular, disclosed herein is a system that can transport and heat thevarious chemical compounds present in the aerosol precursor compositionunder controlled conditions so as to achieve a uniform puff chemistry.In various embodiments, smoking articles as disclosed herein canincorporate certain elements useful to achieve such uniform puffchemistry. For example, a plurality of separate transport elements(e.g., wicks) can be used to transport separate components of theaerosol precursor composition from a reservoir to an aerosolization zone(i.e., at or around a resistive heating element) within the article.Individual transport elements can be formed from different materials(e.g., different fiber types, sintered materials, solid foams, or otherporous materials) and can be formed to have different designs (e.g.,cross-sectional shape, coatings, woven fibers, non-woven fibers, andbundle size) and thus exhibit different transport properties (e.g., flowrate, wicking properties, or capillary action). A plurality of separatereservoirs can be provided to store separate components of the aerosolprecursor composition or separate combinations of components of theaerosol precursor composition. Separate resistive heating elements canbe associated with separate components (or combinations of components)of the aerosol precursor composition such that the separate components(or combinations of components) can be heated separately at differenttemperatures, thermal energy fluxes, or thermal energy inputs.

In some embodiments, a smoking article according to the presentdisclosure can comprise an aerosolization zone including at least oneresistive heating element. The article further can comprise anelectrical power source in electrical connection with the at least oneresistive heating element. Further, the article can comprise an aerosolprecursor composition that is formed of a first component and at least asecond separate component. For example, the first component can be afirst compound or a mixture of compounds, and the second component canbe a second compound or a mixture of compounds. When mixtures ofcompounds are used, it is possible according to the invention for thetwo components of the composition to each include one or more of thesame chemical compounds so long as they include different ratios. Forexample, component 1 can comprise compound A and compound B in an A:Bratio of 80:20 (e.g., based on weight or volume), and component 2 cancomprise compound A and compound B in a 20:80 ratio (based on weight orvolume). Thus, components 1 and 2 are different because they havedifferent ratios of the individual compounds present. Such also canapply where component 1 is formed completely of a single compound whilecomponent 2 includes the same compound in mixture with one or moreadditional compounds. Thus, separate components of the aerosol precursorcomposition can encompass a variety of embodiments. The aerosolprecursor composition specifically is in fluid communication with theaerosolization zone such that the components of the aerosol precursorcomposition transport from one or more reservoirs to the aerosolizationzone, such as via capillary action.

The resistive heating element and the electrical power source in thesmoking article can be removably connected. For example, the smokingarticle can comprise a first unit that is engageable and disengageablewith a second unit, the first unit comprising the aerosolization zoneincluding the resistive heating element, and the second unit comprisingthe electrical power source. The electrical power source can be selectedfrom the group consisting of a battery, a capacitor, and combinationsthereof. The smoking article further can comprise one or more controlcomponents that actuate or regulate current flow from the electricalpower source. Such control components particularly can be located in thesecond unit with the electrical power source.

The first unit of the smoking article can comprise a distal end thatengages the second unit and an opposing, proximate end that includes amouthpiece with an opening at a proximate end thereof. Further, thefirst unit can comprise an air flow path opening into the mouthpiece,and the air flow path can provide for passage of aerosol from theaerosolization zone into the mouthpiece. In specific embodiments, thefirst unit can be disposable. The first unit of the smoking articlespecifically can comprise the reservoirs that can be used for storingthe components of the aerosol precursor composition.

In light of the structure of the smoking article, transport of theaerosol precursor composition to the aerosolization zone can becustomized. For example, different combinations of one or morereservoirs, one or more transport elements, and one or more resistiveheating elements can be used to form a desired aerosol composition.Beneficially, customization can be further achieved by utilizingspecific materials in forming the reservoir(s), using specific materialsin forming the transport element(s), and using multiple heating elementsoperating under the same or different conditions.

When a plurality of transport elements is used, two or more transportelements can transport their respective components of the aerosolprecursor composition to the same resistive heating element. In otherembodiments, separate transport elements can transport their respectivecomponents of the aerosol precursor composition to two or more resistiveheating elements. The resistive heating elements can operate at the sameor different temperatures (e.g., the operating temperatures differing byabout 5° C. or greater). The resistive heating elements can operateunder different sets of conditions. In other words, electrical energycan be controllably delivered from the electrical power source to afirst resistive heating element via a first control scheme, andelectrical energy can be controllably delivered from the electricalpower source to one or more further resistive heating elements via oneor more, different control schemes. For example, the control schemes candiffer in the period of time for which electrical current is deliveredto the resistive heating elements. Likewise, the first resistive heatingelement can function according to a first duty cycle, and one or morefurther resistive heating elements can function according to one or morefurther, different duty cycles.

The aerosol precursor composition used in the smoking article cancomprise a variety of components. For example, the aerosol precursorcomposition can comprise a polyhydric alcohol which, in someembodiments, can be selected from the group consisting of glycerin,propylene glycol, and combinations thereof. The aerosol precursorcomposition also can comprise a medicament, a tobacco component, or atobacco-derived material. In some embodiments, the aerosol precursorcomposition can comprise a slurry or solution including tobacco, atobacco component, or a tobacco-derived material. Further, the aerosolprecursor composition can comprise a flavorant.

The reservoir used in the smoking article for storing the aerosolprecursor composition can take on a variety of forms. Specifically, theaerosol precursor composition can be coated on, adsorbed by, or absorbedin a substrate or a part thereof (e.g., a reservoir formed of a porousmaterial, such as ceramics and porous carbon (e.g., a foam), or afibrous material). Such reservoir can be considered to be at leastpartially saturated with the component of the aerosol precursorcomposition. The aerosol precursor composition specifically can beprovided within a container (i.e., a bottle). Such substrate or bottlecan be characterized as a reservoir.

In particular embodiments, a smoking article according to the presentdisclosure can comprise the following: an aerosolization zone includinga resistive heating element; an aerosol precursor composition in liquidform comprising a first component and a second component; a firstreservoir comprising a porous material that is at least partiallysaturated with the first component of the aerosol precursor composition;a second reservoir comprising the second component of the aerosolprecursor composition; a first transport element providing fluidcommunication between the first reservoir and the aerosolization zone;and a second transport element providing fluid communication between thesecond reservoir and the aerosolization zone. In other embodiments, thesecond reservoir also can comprise a porous material and can be at leastpartially saturated with the second component of the aerosol precursorcomposition. In specific embodiments, the smoking article can comprise aplurality of resistive heating elements. In further embodiments, thesmoking article can comprise a first resistive heating element and asecond resistive heating element, wherein the first transport elementprovides fluid communication between the first reservoir and the firstresistive heating element, and wherein the second transport elementprovides fluid communication between the second reservoir and the secondresistive heating element. Likewise, the smoking article can comprise acontrol component adapted to operate the first resistive heating elementby a first heating protocol and operate the second resistive heatingelement by a second, different heating protocol. More specifically, thesmoking article can comprise an electrical power source, and the controlcomponent can be adapted to control electrical current flow from thepower source to the first resistive heating element and the secondresistive heating element such that the respective heating elements heatto different temperatures or heat for different lengths of time or bothheat to different temperatures and heat for different lengths of time.

In the smoking article, the first transport element can be of adifferent construction than the second transport element. For example,the first transport element and the second transport element can differin one or more of cross-sectional shape, material type, surfacetreatment, and overall dimensions. Further, one or both of the firsttransport element and the second transport element can be a wick havinga defined capillary action. In specific embodiments, the first transportelement and the second transport element can both be wicks.Beneficially, the first wick can have a first wicking rate, and thesecond wick can have a second, different wicking rate. Morespecifically, a wick can comprise a material selected from the groupconsisting of fibrous materials, carbon foams, sintered material,capillary tubes, temperature adaptive polymers, and combinationsthereof. If desired, the first transport element and the secondtransport element can be interconnected in the aerosolization zone.

In specific embodiments, the smoking article can comprise a furtherresistive heating element in substantial contact with one or more of thefirst reservoir, the second reservoir, the first transport element, andthe second transport element. In other embodiments, the smoking articlecan comprise a control component adapted to operate the furtherresistive heating element to warm one or more of the first reservoir,the second reservoir, the first transport element, and the secondtransport element to a temperature that is below a vaporizationtemperature of the respective component of the aerosol precursorcomposition. Such heating element can be useful to pre-heat thecomponent of the aerosol precursor composition to alter thecharacteristics thereof (e.g., reduce viscosity and increase flow rate).

In another aspect, the present invention also provides methods offorming an aerosol in a smoking article from a plurality of aerosolprecursor components. In certain embodiments, such method can comprisethe following steps: activating a power source within the smokingarticle to cause flow of electrical current from the power source to aresistive heating element positioned within an aerosolization zone inthe smoking article; transporting a first component of an aerosolprecursor composition from a first reservoir comprising a porousmaterial that is at least partially saturated with the first componentof the aerosol precursor composition to the aerosolization zone via afirst transport element; transporting a second component of the aerosolprecursor composition from a second reservoir to the aerosolization zonevia a second transport element; and heating the aerosol precursorcomponents to form an aerosol. More particularly, the first aerosolprecursor component can be transported at a first rate, and the secondprecursor component can be transported at second, different rate.

In further embodiments, the method can comprise transporting the firstcomponent of the aerosol precursor composition from the first reservoirto the resistive heating element in the aerosolization zone andtransporting the second component of the aerosol precursor compositionfrom the second reservoir to a second resistive heating element in theaerosolization zone. Further, the method can comprise controlling theflow of electrical current from the power source to the resistiveheating element and to the second resistive heating element such thatresistive heating element is heated by a first heating protocol and thesecond resistive heating element is heated by a second, differentheating protocol. More particularly, the method can comprise controllingthe flow of electrical current from the power source to the resistiveheating element and the second resistive heating element such that therespective heating elements heat to different temperatures or heat fordifferent lengths of time or both heat to different temperatures andheat for different lengths of time. In yet further embodiments, themethod can comprise heating one or more of the first reservoir, thesecond reservoir, the first transport element, and the second transportto a temperature that is below a vaporization temperature of therespective component of the aerosol precursor composition.

BRIEF DESCRIPTION OF THE FIGURES

Having thus described the invention in the foregoing general terms,reference will now be made to the accompanying drawings, which are notnecessarily drawn to scale, and wherein:

FIG. 1 is a perspective view of an example embodiment of a smokingarticle according to the invention, wherein a portion of an outer shellof the article is cut away to reveal the interior components thereof;

FIG. 2 is a cross-section of an example embodiment of a smoking articleaccording to the invention, wherein the cross-section is immediatelydownstream of a transport element surrounded by a resistive heatingelement;

FIG. 3 is a perspective view of an example embodiment of a smokingarticle according to the invention, wherein the article comprises acontrol body and a cartridge that are attachable and detachabletherefrom;

FIG. 4 is a longitudinal cross-section of a smoking article according toan example embodiment of the invention; and

FIG. 5 is a cross-section of the cartridge portion of a smoking articleaccording to another example embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will now be described more fully hereinafter withreference to exemplary embodiments thereof. These exemplary embodimentsare described so that this disclosure will be thorough and complete, andwill fully convey the scope of the invention to those skilled in theart. Indeed, the invention can be embodied in many different forms andshould not be construed as limited to the embodiments set forth herein;rather, these embodiments are provided so that this disclosure willsatisfy applicable legal requirements. As used in the specification, andin the appended claims, the singular forms “a”, “an”, “the”, includeplural referents unless the context clearly dictates otherwise.

The present invention provides articles that use electrical energy toheat a material (preferably without combusting the material to anysignificant degree) to form an inhalable substance, the articles beingsufficiently compact to be considered “hand-held” devices. In certainembodiments, the articles can particularly be characterized as smokingarticles. As used herein, the term is intended to mean an article thatprovides the taste and/or the sensation (e.g., hand-feel or mouth-feel)of smoking a cigarette, cigar, or pipe without substantial combustion ofany component of the article. The term smoking article does notnecessarily indicate that, in operation, the article produces smoke inthe sense of the by-product of combustion or pyrolysis. Rather, smokingrelates to the physical action of an individual in using thearticle—e.g., holding the article, drawing on one end of the article,and inhaling from the article. In further embodiments, the inventivearticles can be characterized as being vapor-producing articles,aerosolization articles, or medicament delivery articles. Thus, thearticles can be arranged so as to provide one or more substances in aninhalable state. In other embodiments, the inhalable substance can besubstantially in the form of a vapor (i.e., a substance that is in thegas phase at a temperature lower than its critical point). In otherembodiments, the inhalable substance can be in the form of an aerosol(i.e., a suspension of fine solid particles or liquid droplets in agas). The physical form of the inhalable substance is not necessarilylimited by the nature of the inventive articles but rather can dependupon the nature of the medium and the inhalable substance itself as towhether it exists in a vapor state or an aerosol state. In someembodiments, the terms can be interchangeable. Thus, for simplicity,these terms as used to describe the invention are understood to beinterchangeable unless stated otherwise.

In one aspect, the present invention provides a smoking article. Thesmoking article generally can include a number of components providedwithin an elongated body, which can be a single, unitary shell or whichcan be formed of two or more separable pieces. For example, a smokingarticle according to one embodiment can comprise a shell (i.e., theelongated body) that can be substantially tubular in shape, such asresembling the shape of a conventional cigarette or cigar. Within theshell can reside all of the components of the smoking article. In otherembodiments, a smoking article can comprise two shells that are joinedand are separable. For example, a control body can comprise a shellcontaining one or more reusable components and having an end thatremovably attaches to a cartridge. The cartridge can comprise a shellcontaining one or more disposable components and having an end thatremovably attaches to the control body. More specific arrangements ofcomponents within the single shell or within the separable control bodyand cartridge are evident in light of the further disclosure providedherein.

Smoking articles useful according to the invention particularly cancomprise some combination of a power source (i.e., an electrical powersource), one or more control components (e.g., tocontrol/actuate/regulate flow of power from the power source to one ormore further components of the article), a heater component, and anaerosol precursor component. The smoking article further can include adefined air flow path through the article such that aerosol generated bythe article can be withdrawn therefrom by a user drawing on the article.Alignment of the components within the article can vary. In specificembodiments, the aerosol precursor component can be located near an endof the article that is proximal to the mouth of a user so as to maximizeaerosol delivery to the user. Other configurations, however, are notexcluded. Generally, the heater component can be positioned sufficientlynear that aerosol precursor component so that heat from the heatercomponent can volatilize the aerosol precursor (as well as one or moreflavorants, medicaments, or the like that can likewise be provided fordelivery to a user) and form an aerosol for delivery to the user. Whenthe heating member heats the aerosol precursor component, an aerosol(alone or including a further inhalable substance) is formed, released,or generated in a physical form suitable for inhalation by a consumer.It should be noted that the foregoing terms are meant to beinterchangeable. As such, the terms release, generate, and form can beinterchangeable, the terms releasing, generating, and forming can beinterchangeable, the terms releases, forms, and generates can beinterchangeable, and the terms released, formed, and generated can beinterchangeable. Specifically, an inhalable substance is released as avapor or aerosol or mixture thereof.

A smoking article according to the invention generally can include anelectrical power source (or electrical power sources) to provide currentflow sufficient to provide various functionalities to the article, suchas resistive heating, powering of indicators, and the like. The powersource for the inventive smoking article can take on variousembodiments. Preferably, the power source is able to deliver sufficientpower to rapidly heat the heating member to provide for aerosolformation and power the article through use for the desired duration oftime. The power source preferably is sized to fit conveniently withinthe article. Examples of useful power sources include lithium ionbatteries that preferably are rechargeable (e.g., a rechargeablelithium-manganese dioxide battery). In particular, lithium polymerbatteries can be used. Other types of batteries—e.g., N50-AAA CADNICAnickel-cadmium cells—can also be used. Even further examples ofbatteries that can be used according to the invention are described inUS Pub. App. No. 2010/0028766, the disclosure of which is incorporatedherein by reference in its entirety. Thin film batteries can be used incertain embodiments of the invention. Any of these batteries orcombinations thereof can be used in the power source, but rechargeablebatteries are preferred because of cost and disposal considerationsassociated with disposable batteries. In embodiments wherein disposablebatteries are provided, the smoking article can include access forremoval and replacement of the battery. Alternatively, in embodimentswhere rechargeable batteries are used, the smoking article can comprisecharging contacts for interaction with corresponding contacts in aconventional recharging unit deriving power from a standard 120-volt ACwall outlet, or other sources such as an automobile electrical system ora separate portable power supply, including USB connections. Means forrecharging the battery can be provided in a portable charging case thatcan include, for example, a relatively larger battery unit that canprovide multiple charges for the relatively smaller batteries present inthe smoking article. The article further can include components forproviding a non-contact inductive recharging system such that thearticle can be charged without being physically connected to an externalpower source. Thus, the article can include components to facilitatetransfer of energy from an electromagnetic field to the rechargeablebattery within the article.

In further embodiments, the power source also can comprise a capacitor.Capacitors are capable of discharging more quickly than batteries andcan be charged between puffs, allowing the battery to discharge into thecapacitor at a lower rate than if it were used to power the heatingmember directly. For example, a supercapacitor—i.e., an electricdouble-layer capacitor (EDLC)—can be used separate from or incombination with a battery. When used alone, the supercapacitor can berecharged before each use of the article. Thus, the invention also caninclude a charger component that can be attached to the smoking articlebetween uses to replenish the supercapacitor.

The smoking article can further include a variety of power managementsoftware, hardware, and/or other electronic control components. Forexample, such software, hardware, and/or electronic controls can includecarrying out charging of the battery, detecting the battery charge anddischarge status, performing power save operations, preventingunintentional or over-discharge of the battery, puff counting, puffdelimiting, puff duration, identifying cartridge status, temperaturecontrol, or the like.

A “controller” or “control component” according to the present inventioncan encompass a variety of elements useful in the present smokingarticle. Moreover, a smoking article according to the invention caninclude one, two, or even more control components that can be combinedinto a unitary element or that can be present at separate locationswithin the smoking article, and individual control components can beutilized for carrying out different control aspects. For example, asmoking article can include a control component that is integral to orotherwise combined with a battery so as to control power discharge fromthe battery. The smoking article separately can include a controlcomponent that controls other aspects of the article. Alternatively, asingle controller can be provided that carries out multiple controlaspects or all control aspects of the article. Likewise, a sensor (e.g.,a puff sensor) used in the article can include a control component thatcontrols the actuation of power discharge from the power source inresponse to a stimulus. The smoking article separately can include acontrol component that controls other aspects of the article.Alternatively, a single controller can be provided in or otherwiseassociated with the sensor for carrying out multiple control aspects orall control aspects of the article. Thus, it can be seen that a varietyof combinations of controllers can be combined in the present smokingarticle to provide the desired level of control of all aspects of thedevice.

The smoking article also can comprise one or more controller componentsuseful for controlling flow of electrical energy from the power sourceto further components of the article, such as to a resistive heatingelement. Specifically, the article can comprise a control component thatactuates current flow from the power source, such as to the resistiveheating element. For example, in some embodiments, the article caninclude a pushbutton that can be linked to a control circuit for manualcontrol of power flow. For example, a consumer can use the pushbutton toturn on the article and/or to actuate current flow into the resistiveheating element. Multiple buttons can be provided for manual performanceof powering the article on and off, and for activating heating foraerosol generation. One or more pushbuttons present can be substantiallyflush with an outer surface of the smoking article.

Instead of (or in addition to) the pushbutton, the inventive article caninclude one or more control components responsive to the consumer'sdrawing on the article (i.e., puff-actuated heating). For example, thearticle can include a switch that is sensitive either to pressurechanges or air flow changes as the consumer draws on the article (i.e.,a puff-actuated switch). Other suitable current actuation/deactuationmechanisms can include a temperature actuated on/off switch or a lippressure actuated switch. An exemplary mechanism that can provide suchpuff-actuation capability includes a Model 163PC01D36 silicon sensor,manufactured by the MicroSwitch division of Honeywell, Inc., Freeport,Ill. With such sensor, the resistive heating element can be activatedrapidly by a change in pressure when the consumer draws on the article.In addition, flow sensing devices, such as those using hot-wireanemometry principles, can be used to cause the energizing of theresistive heating element sufficiently rapidly after sensing a change inair flow. A further puff actuated switch that can be used is a pressuredifferential switch, such as Model No. MPL-502-V, range A, from MicroPneumatic Logic, Inc., Ft. Lauderdale, Fla. Another suitable puffactuated mechanism is a sensitive pressure transducer (e.g., equippedwith an amplifier or gain stage) which is in turn coupled with acomparator for detecting a predetermined threshold pressure. Yet anothersuitable puff actuated mechanism is a vane which is deflected byairflow, the motion of which vane is detected by a movement sensingmeans. Yet another suitable actuation mechanism is a piezoelectricswitch. Also useful is a suitably connected Honeywell MicroSwitchMicrobridge Airflow Sensor, Part No. AWM 2100V from MicroSwitch Divisionof Honeywell, Inc., Freeport, Ill. Further examples of demand-operatedelectrical switches that can be employed in a heating circuit accordingto the present invention are described in U.S. Pat. No. 4,735,217 toGerth et al., which is incorporated herein by reference in its entirety.Other suitable differential switches, analog pressure sensors, flow ratesensors, or the like, will be apparent to the skilled artisan with theknowledge of the present disclosure. A pressure-sensing tube or otherpassage providing fluid connection between the puff actuated switch andan air flow passage within the smoking article can be included so thatpressure changes during draw are readily identified by the switch.

Capacitive sensing components in particular can be incorporated into thedevice in a variety of manners to allow for diverse types of “power-up”and/or “power-down” for one or more components of the device. Capacitivesensing can include the use of any sensor incorporating technology basedon capacitive coupling including, but not limited to, sensors thatdetect and/or measure proximity, position or displacement, humidity,fluid level, pressure, temperature, or acceleration. Capacitive sensingcan arise from electronic components providing for surface capacitance,projected capacitance, mutual capacitance, or self capacitance.Capacitive sensors generally can detect anything that is conductive orhas a dielectric different than that of air. Capacitive sensors, forexample, can replace mechanical buttons (i.e., the push-buttonreferenced above) with capacitive alternatives. Thus, one specificapplication of capacitive sensing according to the invention is a touchcapacitive sensor. For example, a touch pad can be present on thesmoking article that allows the user to input a variety of commands.Most basically, the touch pad can provide for powering the heatingelement much in the same manner as a push button, as already describedabove. In other embodiments, capacitive sensing can be applied near themouthend of the smoking article such that the pressure of the lips onthe smoking article to draw on the article can signal the device toprovide power to the heating element. In addition to touch capacitancesensors, motion capacitance sensors, liquid capacitance sensors, andaccelerometers can be utilized according to the invention to elicit avariety of response from the smoking article. Further, photoelectricsensors also can be incorporated into the inventive smoking article.

Sensors (or control components generally) utilized in the presentarticles can expressly signal for power flow to the heating element soas to heat the aerosol precursor composition and form a vapor or aerosolfor inhalation by a user. Such control components can be adapted tooperate a resistive heating element by a defined heating protocol (e.g.,temperature achieved, duration of heating, etc.). Specifically, thecontrol component can be adapted to control electrical current flow fromthe power source so as to achieve the defined heating protocol.

Sensors also can provide further functions. For example, a “wake-up”sensor can be included. In particular embodiments, a smoking article canbe packaged in a “sleep” mode such that power from the power sourcecannot be delivered to the heating element (or other components of thearticle if desired). The smoking article can include a sensor, such as aphotoelectric sensor or a pull-tab activated sensor or even a capacitivesensor, such that after the smoking article is unpackaged, activation ofthe sensor moves the article from the sleep mode to a working modewherein the article can be used as otherwise described herein. Forexample, the smoking article can be packaged such that light issubstantially prevented from reaching the smoking article. Aphotoelectric sensor on the article then would function to detect whenthe article is removed from the packaging—i.e., is subject to ambientlighting—and transition the article from the sleep mode to a workingmode. Likewise, the sensor can function such that when the article isagain protected from ambient lighting—e.g., placed in a carrying case orstorage case—the article reverts to the sleep mode as a safety measure.Other sensing methods providing similar function likewise can beutilized according to the invention.

When the consumer draws on the mouth end of the smoking article, thecurrent actuation means can permit unrestricted or uninterrupted flow ofcurrent through the resistive heating member to generate heat rapidly.Because of the rapid heating, it can be useful to include currentregulating components to (i) regulate current flow through the heatingmember to control heating of the resistive element and the temperatureexperienced thereby, and (ii) prevent overheating and degradation of theresistive heating element or one or more components carrying the aerosolprecursor composition and/or other flavors or inhalable materials.

The current regulating circuit particularly can be time based.Specifically, such a circuit includes a means for permittinguninterrupted current flow through the heating element for an initialtime period during draw, and a timer means for subsequently regulatingcurrent flow until draw is completed. For example, the subsequentregulation can include the rapid on-off switching of current flow (e.g.,on the order of about every 1 to 50 milliseconds) to maintain theheating element within the desired temperature range. Further,regulation can comprise simply allowing uninterrupted current flow untilthe desired temperature is achieved then turning off the current flowcompletely. The heating member can be reactivated by the consumerinitiating another puff on the article (or manually actuating thepushbutton, depending upon the specific switch embodiment employed foractivating the heater). Alternatively, the subsequent regulation caninvolve the modulation of current flow through the heating element tomaintain the heating element within a desired temperature range. In someembodiments, so as to release the desired dosing of the inhalablesubstance, the heating member can be energized for a duration of about0.2 second to about 5.0 seconds, about 0.3 second to about 4.5 seconds,about 0.5 second to about 4.0 seconds, about 0.5 second to about 3.5seconds, or about 0.6 second to about 3.0 seconds. One exemplarytime-based current regulating circuit can include a transistor, a timer,a comparator, and a capacitor. Suitable transistors, timers,comparators, and capacitors are commercially available and will beapparent to the skilled artisan. Exemplary timers are those availablefrom NEC Electronics as C-1555C and from General Electric Intersil, Inc.as ICM7555, as well as various other sizes and configurations ofso-called “555 Timers”. An exemplary comparator is available fromNational Semiconductor as LM311. Further description of such time-basedcurrent regulating circuits and other control components that can beuseful in the present smoking article are provided in U.S. Pat. Nos.4,922,901, 4,947,874, and 4,947,875, all to Brooks et al., all of whichare incorporated herein by reference in their entireties.

The control components particularly can be configured to closely controlthe amount of heat provided to the resistive heating element. In someembodiments, the current regulating component can function to stopcurrent flow to the resistive heating element once a defined temperaturehas been achieved. Such defined temperature can be in a range that issubstantially high enough to volatilize the aerosol precursorcomposition and any further inhalable substances and provide an amountof aerosol equivalent to a typical puff on a conventional cigarette, asotherwise discussed herein. While the heat needed to volatilize theaerosol precursor composition in a sufficient volume to provide adesired volume for a single puff can vary, it can be particularly usefulfor the heating member to heat to a temperature of about 120° C. orgreater, about 130° C. or greater, about 140° C. or greater, or about160° C. In some embodiments, in order to volatilize an appropriateamount of the aerosol precursor composition, the heating temperature canbe about 180° C. or greater, about 200° C. or greater, about 300° C. orgreater, or about 350° C. or greater. In further embodiments, thedefined temperature for aerosol formation can be about 120° C. to about350° C., about 140° C. to about 300° C., or about 150° C. to about 250°C. It can be particularly desirable, however, to avoid heating totemperatures substantially in excess of about 550° C. in order to avoiddegradation and/or excessive, premature volatilization of the aerosolprecursor composition and/or other construction materials. In someembodiments, a plurality of heating elements can be used, and thecontrol components can be adapted to operate the heating elements underthe same or different conditions. For example, two or more heatingelements can be controlled so as to heat to different temperatures, heatfor different lengths of time, or both. Heating specifically should beat a sufficiently low temperature and for a sufficiently short time soas to avoid degradation and/or significant combustion (preferably anycombustion) of any component of the article. The duration of heating canbe controlled by a number of factors, as discussed in greater detailhereinbelow. Heating temperature and duration can depend upon thedesired volume of aerosol and ambient air that is desired to be drawnthrough the article. The duration, however, can be varied depending uponthe heating rate of the resistive heating element, as the article can beconfigured such that the resistive heating element is energized onlyuntil a desired temperature is reached. Alternatively, duration ofheating can be coupled to the duration of a puff on the article by aconsumer. The heating protocol further can depend upon the specificcomponent of the aerosol precursor composition being heated. Forexample, more volatile components can be heated to lower temperatures orheated for lesser duration of time. Similarly, components forming alesser concentration of the desired aerosol composition can be heatedfor a lesser duration of time so as to release a lower concentration ofthe respective component. Generally, the temperature and time of heatingwill be controlled by one or more components contained in the controlhousing, as noted above.

The current regulating component likewise can cycle the current to theresistive heating element off and on once a defined temperature has beenachieved so as to maintain the defined temperature for a defined periodof time. This tenet can be applied to a plurality of heaters at avariety of different temperatures. Such rapid on-off cycling can be asalready discussed above, and the defined temperature can be an aerosolgenerating temperature as noted above.

Still further, the current regulating component can cycle the current tothe one or more resistive heating elements off and on to maintain afirst temperature that is below an aerosol forming temperature and thenallow an increased current flow in response to a current actuationcontrol component so as to achieve a second temperature that is greaterthan the first temperature and that is an aerosol forming temperature.Such controlling can improve the response time of the article foraerosol formation such that aerosol formation begins almostinstantaneously upon initiation of a puff by a consumer. In someembodiments, the first temperature (which can be characterized as astandby temperature) can be only slightly less than the aerosol formingtemperature defined above. Specifically, the standby temperature can beabout 50° C. to about 150° C., about 70° C. to about 140° C., about 80°C. to about 120° C., or about 90° C. to about 110° C.

In light of the foregoing, it can be seen that a variety of mechanismscan be employed to facilitate actuation/deactuation of current to theone or more resistive heating elements and to other components of thesmoking article. Specifically the article can comprise a component thatregulates a previously initiated current flow from the electrical powersource to the resistive heating element. For example, the inventivearticle can comprise a timer (i.e., a time-based component) forregulating current flow in the article (such as during draw by aconsumer). The article further can comprise a timer responsive switchthat enables and disables current flow to the resistive heating element.Current flow regulation also can comprise use of a capacitor andcomponents for charging and discharging the capacitor at a defined rate(e.g., a rate that approximates a rate at which the heating member heatsand cools). Current flow specifically can be regulated such that thereis uninterrupted current flow through the heating member for an initialtime period during draw, but the current flow can be turned off orcycled alternately off and on after the initial time period until drawis completed. Such cycling can be controlled by a timer, as discussedabove, which can generate a preset switching cycle. In specificembodiments, the timer can generate a periodic digital wave form. Theflow during the initial time period further can be regulated by use of acomparator that compares a first voltage at a first input to a thresholdvoltage at a threshold input and generates an output signal when thefirst voltage is equal to the threshold voltage, which enables thetimer. Such embodiments further can include components for generatingthe threshold voltage at the threshold input and components forgenerating the threshold voltage at the first input upon passage of theinitial time period.

In addition to the above control elements, the smoking article also cancomprise one or more indicators. Such indicators can be lights (e.g.,light emitting diodes) that can provide indication of multiple aspectsof use of the inventive article. For example, a series of lights cancorrespond to the number of puffs for a given cartridge of the smokingarticle. Specifically, the lights can become lit with each puffindicating to a consumer that the cartridge was completely used when alllights were lit. Alternatively, all lights can be lit upon the initialloading of the cartridge, and a light can turn off with each puffindicating to a consumer that the cartridge was completely used when alllights were off. In still other embodiments, only a single indicator canbe present, and lighting thereof can indicate that current is flowing tothe resistive heating element and the article is actively heating. Thiscan ensure that a consumer does not unknowingly leave an articleunattended in an actively heating mode. Still further, one or moreindicators can be provided as an indicator of battery status—e.g.,battery charge, low battery, battery charging, or the like. Further, LEDindicators can be positioned at the distal end of the smoking article tosimulate color changes seen when a conventional cigarette is lit anddrawn on by a user. Although the indicators are described above inrelation to visual indicators in an on/off method, other indices ofoperation also are encompassed. For example, visual indicators also caninclude changes in light color or intensity to show progression of thesmoking experience. Tactile indicators and audio indicators similarlyare encompassed by the invention. Moreover, combinations of suchindicators also can be used in a single article.

A smoking article according to the invention further can comprise aheating member that heats an aerosol precursor component to produce anaerosol for inhalation by a user. In various embodiments, the heatingmember can be formed of a material that provides resistive heating whenan electrical current is applied thereto. Preferably, the resistiveheating element exhibits an electrical resistance making the resistiveheating element useful for providing a sufficient quantity of heat whenelectrical current flows therethrough.

Electrically conductive materials useful as resistive heating elementscan be those having low mass, low density, and moderate resistivity andthat are thermally stable at the temperatures experienced during use.Useful heating elements heat and cool rapidly, and thus provide for theefficient use of energy. Rapid heating of the element can be beneficialto provide almost immediate volatilization of an aerosol precursorcomposition in proximity thereto. Rapid cooling prevents substantialvolatilization (and hence waste) of the aerosol precursor compositionduring periods when aerosol formation is not desired. Such heatingelements also permit relatively precise control of the temperature rangeexperienced by the aerosol precursor composition, especially when timebased current control is employed. Useful electrically conductivematerials preferably are thermally stable and chemically non-reactivewith the materials being heated (e.g., aerosol precursor compositionsand other inhalable substance materials) so as not to adversely affectthe flavor or content of the aerosol or vapor that is produced.Exemplary, non-limiting, materials that can be used as the electricallyconductive material include carbon, graphite, carbon/graphitecomposites, metals, metallic and non-metallic carbides, nitrides,silicides, inter-metallic compounds, cermets, metal alloys, and metalfoils. In particular, refractory materials can be useful. Various,different materials can be mixed to achieve the desired properties ofresistivity, mass, and thermal conductivity. In specific embodiments,metals that can be utilized include, for example, nickel, chromium,alloys of nickel and chromium (e.g., nichrome), and steel. Materialsthat can be useful for providing resistive heating are described in U.S.Pat. No. 5,060,671 to Counts et al.; U.S. Pat. No. 5,093,894 to Deevi etal.; U.S. Pat. No. 5,224,498 to Deevi et al.; U.S. Pat. No. 5,228,460 toSprinkel Jr., et al.; U.S. Pat. No. 5,322,075 to Deevi et al.; U.S. Pat.No. 5,353,813 to Deevi et al.; U.S. Pat. No. 5,468,936 to Deevi et al.;U.S. Pat. No. 5,498,850 to Das; U.S. Pat. No. 5,659,656 to Das; U.S.Pat. No. 5,498,855 to Deevi et al.; U.S. Pat. No. 5,530,225 toHajaligol; U.S. Pat. No. 5,665,262 to Hajaligol; U.S. Pat. No. 5,573,692to Das et al.; and U.S. Pat. No. 5,591,368 to Fleischhauer et al., thedisclosures of which are incorporated herein by reference in theirentireties.

The resistive heating element can be provided in a variety forms, suchas in the form of a foil, a foam, discs, spirals, fibers, wires, films,yarns, strips, ribbons, or cylinders, as well as irregular shapes ofvarying dimensions. In some embodiments, a resistive heating elementaccording to the present invention can be a conductive substrate, suchas described in co-pending U.S. patent application Ser. No. 13/432,406,filed Mar. 28, 2012, the disclosure of which is incorporated herein byreference in its entirety.

Beneficially, the resistive heating element can be provided in a formthat enables the heating element to be positioned in intimate contactwith or in close proximity to the aerosol precursor composition, or oneor more components thereof. In other embodiments, the resistive heatingelement can be provided in a form such that the aerosol precursorcomposition can be transported to the resistive heating element foraerosolization. Such transport can be via a variety of means. Forexample, transport of components for aerosolization can comprise wicking(i.e., transport via capillary action), diffusion, thermally drivendiffusion, surface diffusion, passive flow, and active pumping ormechanically driven flow. In some embodiments, one or more valves can beutilized to control transport of the components for aerosolization. Assuch, the components for aerosolization (including aerosol formers andother inhalable materials) can be provided in liquid form in one or morereservoirs positioned sufficiently away from the resistive heatingelement to prevent premature aerosolization, but positioned sufficientlyclose to the resistive heating element to facilitate transport of theaerosol precursor composition, in the desired amount, to the resistiveheating element for aerosolization.

In certain embodiments, a smoking article according to the presentinvention can include tobacco, a tobacco component, or a tobacco-derivedmaterial (i.e., a material that is found naturally in tobacco that canbe isolated directly from the tobacco or synthetically prepared). Thetobacco that is employed can include, or can be derived from, tobaccossuch as flue-cured tobacco, burley tobacco, Oriental tobacco, Marylandtobacco, dark tobacco, dark-fired tobacco and Rustica tobacco, as wellas other rare or specialty tobaccos, or blends thereof. Variousrepresentative tobacco types, processed types of tobaccos, and types oftobacco blends are set forth in U.S. Pat. No. 4,836,224 to Lawson etal.; U.S. Pat. No. 4,924,888 to Perfetti et al.; U.S. Pat. No. 5,056,537to Brown et al.; U.S. Pat. No. 5,159,942 to Brinkley et al.; U.S. Pat.No. 5,220,930 to Gentry; U.S. Pat. No. 5,360,023 to Blakley et al.; U.S.Pat. No. 6,701,936 to Shafer et al.; U.S. Pat. No. 6,730,832 toDominguez et al., U.S. Pat. No. 7,011,096 to Li et al.; U.S. Pat. No.7,017,585 to Li et al.; U.S. Pat. No. 7,025,066 to Lawson et al.; USPat. App. Pub. No. 2004/0255965 to Perfetti et al.; PCT Pub. WO 02/37990to Bereman; and Bombick et al., Fund. Appl. Toxicol., 39, p. 11-17(1997); the disclosures of which are incorporated herein by reference intheir entireties. Descriptions of various types of tobaccos, growingpractices, harvesting practices, and curing practices are set forth inTobacco Production, Chemistry and Technology, Davis et al. (Eds.)(1999).

The smoking article can incorporate tobacco additives of the type thatare traditionally used for the manufacture of tobacco products. Thoseadditives can include the types of materials used to enhance the flavorand aroma of tobaccos used for the production of cigars, cigarettes,pipes, and the like. For example, those additives can include variouscigarette casing and/or top dressing components. See, for example, U.S.Pat. No. 3,419,015 to Wochnowski; U.S. Pat. No. 4,054,145 to Berndt etal.; U.S. Pat. No. 4,887,619 to Burcham, Jr. et al.; U.S. Pat. No.5,022,416 to Watson; U.S. Pat. No. 5,103,842 to Strang et al.; and U.S.Pat. No. 5,711,320 to Martin; the disclosures of which are incorporatedherein by reference in their entireties. Preferred casing materialsinclude water, sugars and syrups (e.g., sucrose, glucose and highfructose corn syrup), humectants (e.g. glycerin or propylene glycol),and flavoring agents (e.g., cocoa and licorice). Those added componentsalso include top dressing materials (e.g., flavoring materials, such asmenthol). See, for example, U.S. Pat. No. 4,449,541 to Mays et al., thedisclosure of which is incorporated herein by reference in its entirety.The selection of particular casing and top dressing components isdependent upon factors such as the sensory characteristics that aredesired, and the selection and use of those components will be readilyapparent to those skilled in the art of cigarette design andmanufacture. See, Gutcho, Tobacco Flavoring Substances and Methods,Noyes Data Corp. (1972) and Leffingwell et al., Tobacco Flavoring forSmoking Products (1972), the disclosures of which are incorporatedherein by reference in their entireties. Further materials that can beadded include those disclosed in U.S. Pat. No. 4,830,028 to Lawson etal. and US Pat. Pub. No. 2008/0245377 to Marshall et al., thedisclosures of which are incorporated herein by reference in theirentireties.

Various manners and methods for incorporating tobacco into smokingarticles, and particularly smoking articles that are designed so as tonot purposefully burn virtually all of the tobacco within those smokingarticles, are set forth in U.S. Pat. No. 4,947,874 to Brooks et al.;U.S. Pat. No. 7,647,932 to Cantrell et al., US Pat. App. Pub. No.2005/0016549 to Banerjee et al.; and US Pat. App. Pub. No. 2007/0215167to Crooks et al.; the disclosures of which are incorporated herein byreference in their entireties.

The aerosol precursor or vapor precursor composition can comprise one ormore different components. For example, the aerosol precursor caninclude a polyhydric alcohol (e.g., glycerin, propylene glycol, or amixture thereof). Representative types of further aerosol precursorcompositions are set forth in U.S. Pat. No. 4,793,365 to Sensabaugh, Jr.et al.; U.S. Pat. No. 5,101,839 to Jakob et al.; PCT WO 98/57556 toBiggs et al.; and Chemical and Biological Studies on New CigarettePrototypes that Heat Instead of Burn Tobacco, R. J. Reynolds TobaccoCompany Monograph (1988); the disclosures of which are incorporatedherein by reference. In some embodiments, an aerosol precursorcomposition can produce a visible aerosol upon the application ofsufficient heat thereto (and cooling with air, if necessary), and suchaerosol precursor composition can produce an aerosol that can beconsidered to be “smoke-like.” In some embodiments, however, the aerosolprecursor component can be heated to form an aerosol that issubstantially invisible to the naked eye and can be identified primarilyby the flavor and/or aroma and/or texture apparent to the consumer.Thus, the term “aerosol precursor composition” can broadly encompasscompositions (or components thereof) that produce a visible aerosol aswell as compositions (or components thereof) that produce an aerosolthat is identifiably by further characteristics (e.g., other thanvisibility). For example, a polyhydric alcohol can be considered to bean aerosol precursor that can produce a visible aerosol. Othercomponents, such as some flavors or medicaments, can be considered to bean aerosol precursor that can produce an aerosol that is identifiable byfurther characteristics. An exemplary aerosol precursor composition canbe chemically simple, relative to the chemical nature of the smokeproduced by burning tobacco. If desired, aerosol precursor compositionscan include other liquid materials, such as water. For example, aerosolprecursor compositions can incorporate mixtures of glycerin and water,or mixtures of propylene glycol and water, or mixtures of propyleneglycol and glycerin, or mixtures of propylene glycol, glycerin, andwater. Exemplary aerosol precursor compositions also include those typesof materials incorporated within devices available through AtlantaImports Inc., Acworth, Ga., USA., as an electronic cigar having thebrand name E-CIG, which can be employed using associated SmokingCartridges Type C1a, C2a, C3a, C4a, C1b, C2b, C3b and C4b; and as RuyanAtomizing Electronic Pipe and Ruyan Atomizing Electronic Cigarette fromRuyan SBT Technology and Development Co., Ltd., Beijing, China.

Further tobacco materials, such as a tobacco aroma oil, a tobaccoessence, a spray dried tobacco extract, a freeze dried tobacco extract,tobacco dust, or the like can be combined with the vapor precursor oraerosol precursor composition. As used herein, the term “tobaccoextract” means components separated from, removed from, or derived from,tobacco using tobacco extraction processing conditions and techniques.Purified extracts (including extracts from other botanicals)particularly can be used. Typically, tobacco extracts are obtained usingsolvents, such as solvents having an aqueous nature (e.g., water) ororganic solvents (e.g., alcohols, such as ethanol or alkanes, such ashexane). As such, extracted tobacco components are removed from tobaccoand separated from the unextracted tobacco components; and for extractedtobacco components that are present within a solvent, (i) the solventcan be removed from the extracted tobacco components, or (ii) themixture of extracted tobacco components and solvent can be used as such.For example, tobacco can be subjected to extraction conditions usingwater as a solvent; the resulting aqueous extract of tobacco then isseparated from the water insoluble pulp; and then (i) the mixture ofaqueous extract of tobacco within water can be used as such, or (ii)substantial amounts of the water can be removed from extracted tobaccocomponents (e.g., using spray drying or freeze drying techniques) inorder to provide a tobacco extract in powder form. Preferred tobaccoextracts incorporate numerous components that are separated from,removed from, or derived from, tobacco; and are not obtained usingtobacco extraction processes conditions that are highly selective to asingle component (e.g., preferred extracts are not high nicotine contentextracts, or extracts that can be characterized as relatively purenicotine compositions). As such, exemplary preferred tobacco extractspossess less than 45 percent nicotine, often less than 35 percentnicotine, and frequently less than 25 percent nicotine, on the basis ofthe total extract weight with solvent removed (e.g., on a dry weightbasis when the solvent is water). In addition, highly preferred tobaccoextracts are highly aromatic and flavorful, and hence introducedesirable sensory characteristics to the aerosol produced by the smokingarticles incorporating those extracts. Exemplary types of tobaccoextracts, tobacco essences, solvents, tobacco extraction processingconditions and techniques, and tobacco extract collection and isolationprocedures, are set forth in Australia Pat. No. 276,250 to Schachner;U.S. Pat. No. 2,805,669 to Meriro; U.S. Pat. No. 3,316,919 to Green etal.; U.S. Pat. No. 3,398,754 to Tughan; U.S. Pat. No. 3,424,171 toRooker; U.S. Pat. No. 3,476,118 to Luttich; U.S. Pat. No. 4,150,677 toOsborne; U.S. Pat. No. 4,131,117 to Kite; U.S. Pat. No. 4,506,682 toMuller; U.S. Pat. No. 4,986,286 to Roberts et al.; U.S. Pat. No.5,005,593 to Fagg; U.S. Pat. No. 5,065,775 to Fagg; U.S. Pat. No.5,060,669 to White et al.; U.S. Pat. No. 5,074,319 to White et al.; U.S.Pat. No. 5,099,862 to White et al.; U.S. Pat. No. 5,121,757 to White etal.; U.S. Pat. No. 5,131,415 to Munoz et al.; U.S. Pat. No. 5,230,354 toSmith et al.; U.S. Pat. No. 5,235,992 to Sensabaugh; U.S. Pat. No.5,243,999 to Smith; U.S. Pat. No. 5,301,694 to Raymond; U.S. Pat. No.5,318,050 to Gonzalez-Parra et al.; U.S. Pat. No. 5,435,325 to Clapp etal.; and U.S. Pat. No. 5,445,169 to Brinkley et al.; the disclosures ofwhich are incorporated herein by reference in their entireties.

The smoking article further can comprise one or more flavors,medicaments, or other inhalable materials. For example, liquid nicotinecan be used. Such further materials can be included in the aerosolprecursor or vapor precursor composition. Thus, the aerosol precursor orvapor precursor composition can be described as comprising an inhalablesubstance that is not necessarily produced as a visible aerosol. Suchinhalable substance can include flavors, medicaments, and othermaterials as discussed herein. Particularly, an inhalable substancedelivered using a smoking article according to the present invention cancomprise a tobacco component or a tobacco-derived material. For example,the aerosol precursor composition can comprise a slurry or solution withtobacco, a tobacco component, or a tobacco-derived material.

The various components of the aerosol precursor composition (e.g.,polyhydric alcohols, flavors, medicaments, etc.) can be provided in oneor more reservoirs. As such, defined aliquots of the various componentscan be separately or simultaneously delivered to the resistive heatingelement for aerosolization in an air stream to be inhaled by a user. Thecomponents of the aerosol precursor composition can be transported to anaerosolization zone so as to be in proximity to a heating element. Theproximity preferably is sufficient such that heating of the resistiveheating element provides heat to the components sufficient to volatilizeand release the components in an inhalable form.

A wide variety of types of flavoring agents, or materials that alter thesensory or organoleptic character or nature of the mainstream aerosol ofthe smoking article can be employed. Such flavoring agents can beprovided from sources other than tobacco, can be natural or artificialin nature, and can be employed as concentrates or flavor packages. Suchagents can be supplied directly to the resistive heating element or canbe provided on a substrate positioned within the aerosolization zone soas to be stored separate from the further components of the aerosolprecursor composition. Exemplary flavoring agents include vanillin,ethyl vanillin, cream, tea, coffee, fruit (e.g., apple, cherry,strawberry, peach and citrus flavors, including lime and lemon), maple,menthol, mint, peppermint, spearmint, wintergreen, nutmeg, clove,lavender, cardamom, ginger, honey, anise, sage, cinnamon, sandalwood,jasmine, cascarilla, cocoa, licorice, and flavorings and flavor packagesof the type and character traditionally used for the flavoring ofcigarette, cigar, and pipe tobaccos. Syrups, such as high fructose cornsyrup, also can be employed. Flavoring agents also can include acidic orbasic characteristics (e.g., organic acids, such as levulinic acid,succinic acid, and pyruvic acid). The flavoring agents can be combinedwith the aerosol-generating material if desired. Exemplary plant-derivedcompositions that can be used are disclosed in U.S. application Ser. No.12/971,746 to Dube et al. and U.S. application Ser. No. 13/015,744 toDube et al., the disclosures of which are incorporated herein byreference in their entireties. The selection of such further componentscan vary based upon factors such as the sensory characteristics that aredesired for the present article, and the present invention is intendedto encompass any such further components that can be readily apparent tothose skilled in the art of tobacco and tobacco-related ortobacco-derived products. See, Gutcho, Tobacco Flavoring Substances andMethods, Noyes Data Corp. (1972) and Leffingwell et al., TobaccoFlavoring for Smoking Products (1972), the disclosures of which areincorporated herein by reference in their entireties. Any of thematerials, such as flavorings, casings, and the like that can be usefulin combination with a tobacco material to affect sensory propertiesthereof, including organoleptic properties, such as already describedherein, can be combined with the aerosol precursor composition. Organicacids particularly can be incorporated into the aerosol precursor toaffect the flavor, sensation, or organoleptic properties of medicaments,such as nicotine, that can be combined with the aerosol precursor. Forexample, organic acids, such as levulinic acid, lactic acid, and pyruvicacid, can be included in the aerosol precursor with nicotine in amountsup to being equimolar (based on total organic acid content) with thenicotine. Any combination of organic acids can be used. For example, theaerosol precursor can include about 0.1 to about 0.5 moles of levulinicacid per one mole of nicotine, about 0.1 to about 0.5 moles of pyruvicacid per one mole of nicotine, about 0.1 to about 0.5 moles of lacticacid per one mole of nicotine, or combinations thereof, up to aconcentration wherein the total amount of organic acid present isequimolar to the total amount of nicotine present in the aerosolprecursor.

The aerosol precursor composition can take on a variety of conformationsbased upon the various amounts of materials utilized therein. Forexample, a useful aerosol precursor composition can comprise up to about98% by weight up to about 95% by weight, or up to about 90% by weight ofa polyol. This total amount can be split in any combination between twoor more different polyols. For example, one polyol can comprise about50% to about 90%, about 60% to about 90%, or about 75% to about 90% byweight of the aerosol precursor, and a second polyol can comprise about2% to about 45%, about 2% to about 25%, or about 2% to about 10% byweight of the aerosol precursor. A useful aerosol precursor also cancomprise up to about 25% by weight, about 20% by weight or about 15% byweight water—particularly about 2% to about 25%, about 5% to about 20%,or about 7% to about 15% by weight water. Flavors and the like (whichcan include medicaments, such as nicotine) can comprise up to about 10%,up to about 8%, or up to about 5% by weight of the aerosol precursor.

As a non-limiting example, an aerosol precursor according to theinvention can comprise glycerol, propylene glycol, water, nicotine, andone or more flavors. Specifically, the glycerol can be present in anamount of about 70% to about 90% by weight, about 70% to about 85% byweight, or about 75% to about 85% by weight, the propylene glycol can bepresent in an amount of about 1% to about 10% by weight, about 1% toabout 8% by weight, or about 2% to about 6% by weight, the water can bepresent in an amount of about 10% to about 20% by weight, about 10% toabout 18% by weight, or about 12% to about 16% by weight, the nicotinecan be present in an amount of about 0.1% to about 5% by weight, about0.5% to about 4% by weight, or about 1% to about 3% by weight, and theflavors can be present in an amount of up to about 5% by weight, up toabout 3% by weight, or up to about 1% by weight, all amounts being basedon the total weight of the aerosol precursor. One specific, non-limitingexample of an aerosol precursor comprises about 75% to about 80% byweight glycerol, about 13% to about 15% by weight water, about 4% toabout 6% by weight propylene glycol, about 2% to about 3% by weightnicotine, and about 0.1% to about 0.5% by weight flavors. The nicotine,for example, can be a high nicotine content tobacco extract.

The amount of aerosol precursor composition that is used within thesmoking article is such that the article exhibits acceptable sensory andorganoleptic properties, and desirable performance characteristics.Typically, the amount of aerosol-generating material incorporated intothe smoking article is in the range of about 1.5 g or less, about 1 g orless, or about 0.5 g or less. The amount of aerosol precursorcomposition can be dependent upon factors such as the number of puffsdesired per cartridge used with the smoking article. It is desirable forthe aerosol-generating composition not to introduce significant degreesof unacceptable off-taste, filmy mouth-feel, or an overall sensoryexperience that is significantly different from that of a traditionaltype of cigarette that generates mainstream smoke by burning tobacco cutfiller. The selection of the particular aerosol precursor components andreservoir material, the amounts of those components used, and the typesof tobacco material used, can be altered in order to control the overallchemical composition of the mainstream aerosol produced by the smokingarticle.

The amount of aerosol released by the inventive article can vary.Preferably, the article is configured with a sufficient amount of theindividual components of the aerosol precursor composition to functionat a sufficient temperature for a sufficient time to release a desiredcontent of aerosolized materials over a course of use. The content canbe provided in a single inhalation from the article or can be divided soas to be provided through a number of puffs from the article over arelatively short length of time (e.g., less than 30 minutes, less than20 minutes, less than 15 minutes, less than 10 minutes, or less than 5minutes). For example, the article can provide nicotine in an amount ofabout 0.01 mg to about 0.5 mg, about 0.05 mg to about 0.3 mg, or about0.1 mg to about 0.2 mg per puff on the article. In other embodiments, adesired amount can be characterized in relation to the content of wettotal particulate matter delivered based on puff duration and volume.For example, the article can deliver at least 0.1 mg of wet totalparticulate matter on each puff, for a defined number of puffs (asotherwise described herein), when smoked under standard FTC smokingconditions of 2 second, 35 ml puffs. Such testing can be carried outusing any standard smoking machine. In other embodiments, the content ofwet total particulate matter (WTPM) delivered under the same conditionson each puff (of approximately 2 seconds in duration) can be at least1.5 mg, at least 1.7 mg, at least 2.0 mg, at least 2.5 mg, at least 3.0mg, about 1.0 mg to about 5.0 mg, about 1.5 mg to about 4.0 mg, about2.0 mg to about 4.0 mg, or about 2.0 mg to about 3.0 mg. Such values canrelate to the content of aerosol precursor composition that is deliveredalone or in combination with any further inhalable substances that arebeing delivered by the article. For purposes of calculations, an averagepuff time of about 2 seconds can deliver a puff volume of about 5 ml toabout 100 ml, about 15 ml to about 70 ml, about 20 ml to about 60 ml, orabout 25 ml to about 50 ml. Such total puff volume can provide, incertain embodiments, the WTPM content previously described. Thus, WTPMas delivered can be characterized in relation to the total puffvolume—e.g., about 1 mg to about 4 mg WTPM in a total puff volume ofabout 25 ml to about 75 ml. Such characterization is inclusive of allpuff volume values and WTPM values otherwise described herein. A smokingarticle according to the invention can be configured to provide anynumber of puffs calculable by the total amount of components of theaerosol precursor composition to be delivered (or the total WTPM to bedelivered) divided by the amount to be delivered per puff. The one ormore reservoirs can be loaded with the appropriate amount of thecomponents of the aerosol precursor composition to achieve the desirednumber of puffs and/or the desired total amount of material to bedelivered.

In further embodiments, heating can be characterized in relation to theamount of aerosol to be generated. Specifically, the article can beconfigured to provide an amount of heat necessary to generate a definedvolume of aerosol (e.g., about 5 ml to about 100 ml, or any other volumedeemed useful in a smoking article, such as otherwise described herein).In certain embodiments, the amount of heat generated can be measured inrelation to a two second puff providing about 35 ml of aerosol at aheater temperature of about 290° C. In some embodiments, the articlepreferably can provide about 1 to about 50 Joules of heat per second(J/s), about 2 J/s to about 40 J/s, about 3 J/s to about 35 J/s, orabout 5 J/s to about 30 J/s.

The resistive heating element preferably is in electrical connectionwith the power source of the smoking article such that electrical energycan be provided to the resistive heating element to produce heat andsubsequently aerosolize the aerosol precursor composition and any otherinhalable substance provided by the smoking article. Such electricalconnection can be permanent (e.g., hard wired) or can be removable(e.g., wherein the resistive heating element is provided in a cartridgethat can be attached to and detached from a control body that includesthe power source).

Although a variety of materials for use in a smoking article accordingto the present invention have been described above—such as heaters,batteries, capacitors, switching components, aerosol precursors, and thelike, the invention should not be construed as being limited to only theexemplified embodiments. Rather, one of skill in the art can recognizebased on the present disclosure similar components in the field that canbe interchanged with any specific component of the present invention.For example, U.S. Pat. No. 5,261,424 to Sprinkel, Jr. disclosespiezoelectric sensors that can be associated with the mouth-end of adevice to detect user lip activity associated with taking a draw andthen trigger heating; U.S. Pat. No. 5,372,148 to McCafferty et al.discloses a puff sensor for controlling energy flow into a heating loadarray in response to pressure drop through a mouthpiece; U.S. Pat. No.5,967,148 to Harris et al. discloses receptacles in a smoking devicethat include an identifier that detects a non-uniformity in infraredtransmissivity of an inserted component and a controller that executes adetection routine as the component is inserted into the receptacle; U.S.Pat. No. 6,040,560 to Fleischhauer et al. describes a defined executablepower cycle with multiple differential phases; U.S. Pat. No. 5,934,289to Watkins et al. discloses photonic-optronic components; U.S. Pat. No.5,954,979 to Counts et al. discloses means for altering draw resistancethrough a smoking device; U.S. Pat. No. 6,803,545 to Blake et al.discloses specific battery configurations for use in smoking devices;U.S. Pat. No. 7,293,565 to Griffen et al. discloses various chargingsystems for use with smoking devices; US 2009/0320863 by Fernando et al.discloses computer interfacing means for smoking devices to facilitatecharging and allow computer control of the device; US 2010/0163063 byFernando et al. discloses identification systems for smoking devices;and WO 2010/003480 by Flick discloses a fluid flow sensing systemindicative of a puff in an aerosol generating system; all of theforegoing disclosures being incorporated herein by reference in theirentireties. Further examples of components related to electronic aerosoldelivery articles and disclosing materials or components that can beused in the present article include U.S. Pat. No. 4,735,217 to Gerth etal.; U.S. Pat. No. 5,249,586 to Morgan et al.; U.S. Pat. No. 5,666,977to Higgins et al.; U.S. Pat. No. 6,053,176 to Adams et al.; U.S. Pat.No. 6,164,287 to White; U.S. Pat. No. 6,196,218 to Voges; U.S. Pat. No.6,810,883 to Felter et al.; U.S. Pat. No. 6,854,461 to Nichols; U.S.Pat. No. 7,832,410 to Hon; U.S. Pat. No. 7,513,253 to Kobayashi; U.S.Pat. No. 7,896,006 to Hamano; U.S. Pat. No. 6,772,756 to Shayan; US Pat.Pub. Nos. 2009/0095311, 2006/0196518, 2009/0126745, and 2009/0188490 toHon; US Pat. Pub. No. 2009/0272379 to Thorens et al.; US Pat. Pub. Nos.2009/0260641 and 2009/0260642 to Monsees et al.; US Pat. Pub. Nos.2008/0149118 and 2010/0024834 to Oglesby et al.; US Pat. Pub. No.2010/0307518 to Wang; and WO 2010/091593 to Hon. A variety of thematerials disclosed by the foregoing documents can be incorporated intothe present devices in various embodiments, and all of the foregoingdisclosures are incorporated herein by reference in their entireties.

Although an article according to the invention can take on a variety ofembodiments, as discussed in detail below, the use of the article by aconsumer will be similar in scope. In particular, the article can beprovided as a single unit or as a plurality of components that arecombined by the consumer for use and then are dismantled by the consumerthereafter. Generally, a smoking article according to the invention cancomprise a first unit that is engageable and disengeagable with a secondunit, the first unit comprising the resistive heating element, and thesecond unit comprising the electrical power source. In some embodiments,the second unit further can comprise one or more control components thatactuate or regulate current flow from the electrical power source. Thefirst unit can comprise a distal end that engages the second unit and anopposing, proximate end that includes a mouthpiece (or simply themouthend) with an opening at a proximate end thereof. The first unit cancomprise an air flow path opening into the mouthpiece of the first unit,and the air flow path can provide for passage of aerosol formed from theresistive heating element into the mouthpiece. In preferred embodiments,the first unit can be disposable. Likewise, the second unit can bereusable.

More specifically, a smoking article according to the invention can havea reusable control body that is substantially cylindrical in shapehaving a connecting end and an opposing, closed end. The closed end ofthe control housing can include one or more indicators of active use ofthe article. The article further can comprise a cartridge with aconnecting end that engages the connecting end of the control body andwith an opposing, mouthend. To use the article, the consumer can connecta connecting end of the cartridge to the connecting end of the controlbody or otherwise combine the cartridge with the control body so thatthe article is operable as discussed herein. In some embodiments, theconnecting ends of the control body and the cartridge can be threadedfor a screw-type engagement. In other embodiments, the connecting endscan have a press-fit engagement.

During use, the consumer initiates heating of the resistive heatingelement, the heat produced by the resistive heating element aerosolizesthe components of the aerosol precursor composition. Such heatingreleases at least a portion of the aerosol precursor composition in theform of an aerosol and such aerosol is provided within a space insidethe cartridge (e.g., an aerosolization zone) that is in fluidcommunication with the mouthend of the cartridge. When the consumerinhales on the mouth end of the cartridge, air is drawn through thecartridge, and the combination of the drawn air and the aerosol isinhaled by the consumer as the drawn materials exit the mouth end of thecartridge (and any optional mouthpiece present) into the mouth of theconsumer. To initiate heating, the consumer can actuate a pushbutton,capacitive sensor, or similar component that causes the resistiveheating element to receive electrical energy from the battery or otherenergy source (such as a capacitor). The electrical energy can besupplied for a pre-determined length of time or can be manuallycontrolled. Preferably, flow of electrical energy does not substantiallyproceed in between puffs on the article (although energy flow canproceed to maintain a baseline temperature greater than ambienttemperature—e.g., a temperature that facilitates rapid heating to theactive heating temperature). In further embodiments, heating can beinitiated by the puffing action of the consumer through use of varioussensors, as otherwise described herein. Once the puff is discontinued,heating will stop or be reduced. When the consumer has taken asufficient number of puffs so as to have released a sufficient amount ofthe inhalable substance (e.g., an amount sufficient to equate to atypical smoking experience), the cartridge can be removed from thecontrol housing and discarded. Indication that the cartridge is spent(i.e., the aerosol precursor composition has been substantially removedby the consumer) can be provided. In some embodiments, a singlecartridge can provide more than a single smoking experience and thus canprovide a sufficient content of aerosol precursor composition tosimulate as much as full pack of conventional cigarettes or even more.

The foregoing description of use of the article can be applied to thevarious embodiments described through minor modifications, which can beapparent to the person of skill in the art in light of the furtherdisclosure provided herein. The above description of use, however, isnot intended to limit the use of the inventive article but is providedto comply with all necessary requirements of disclosure of the presentinvention.

Referring now to FIG. 1, a smoking article 10 according to the inventiongenerally can comprise a shell 15 and a plurality of components providedwithin the shell. The article can be characterized as having a mouthend11 (i.e., the end upon which a consumer can draw to inhale aerosol fromthe article), and a distal end 12. The illustrated article is providedas a single unitary device (however, line A indicates an optionaldemarcation whereby the device can be two separate components that arejoined together, either removably or permanently, such as by gluing). Aswill be evident from the further disclosure herein, it can be preferablefor further embodiments of the article to be formed of two or moredetachable units, each housing separate components of the article. Thevarious components shown in the embodiment of FIG. 1 can be present inother embodiments, including embodiments formed of multiple units.

The article 10 according to the invention can have an overall shape thatcan be defined as being substantially rod-like or substantially tubularshaped or substantially cylindrically shaped. As illustrated in FIG. 1,the article has a substantially round cross-section; however, othercross-sectional shapes (e.g., oval, square, triangle, etc.) also areencompassed by the present disclosure. Such language that is descriptiveof the physical shape of the article can also be applied to theindividual units of the article in embodiments comprising multipleunits, such as a control body and a cartridge.

The shell 15 of the smoking article 10 can be formed of any materialsuitable for forming and maintaining an appropriate conformation, suchas a tubular shape, and for retaining therein the suitable components ofthe article. The shell can be formed of a single wall, as shown inFIG. 1. In some embodiments, the shell can be formed of a material(natural or synthetic) that is heat resistant so as to retain itsstructural integrity—e.g., does not degrade—at least at a temperaturethat is the heating temperature provided by the resistive heatingelement, as further discussed herein. In some embodiments, a heatresistant polymer can be used. In other embodiments, the shell can beformed from paper, such as a paper that is substantially straw-shaped.As further discussed herein, the shell, such as a paper tube, can haveone or more layers associated therewith that function to substantiallyprevent movement of vapor therethrough. In one example, an aluminum foillayer can be laminated to one surface of the shell. Ceramic materialsalso can be used.

In further embodiments, a smoking article 10 according to the inventioncan include a variety of materials that can provide specificfunctionalities. For example, FIG. 2 shows a cross-section of a smokingarticle 10 near the mouthend 11 of the article. In this embodiment, aninsulator layer 70 can be included, specifically in the area of theshell 15 where the resistive heating element 50 is present, so as not tounnecessarily move heat away from the resistive heating element. Theinsulator layer, however, can be present in other areas of the article(including substantially the entire length of the article). For example,in embodiments wherein the article comprises a control body and aseparate cartridge, the control body can include an insulator layer, ifdesired. The insulator layer 70 can be formed of a paper or otherfibrous material, such as a cellulose. In such embodiments, so as toprevent movement of the aerosol precursor composition outward toward thesurface of the article, it can be useful to include a barrier layer 75,which can comprise any material that is impervious to the particularcomponents of the aerosol precursor composition, such as a metal foil,waxed paper, or the like. Further, the shell 15 can include an overwrap115 on at least a portion thereof, such as at the mouthend 11 of thearticle, and such overwrap also can be formed of multiple layers. Theoverwrap can be, for example, a typical wrapping paper in a cigarette.The overwrap particularly can comprise a material typically used in afilter element of a conventional cigarette, such as cellulose acetateand thus can function to provide the sensation of a conventionalcigarette in the mouth of a consumer. Exemplary types of wrappingmaterials, wrapping material components, and treated wrapping materialsthat can be used in an overwrap in the present invention are describedin U.S. Pat. No. 5,105,838 to White et al.; U.S. Pat. No. 5,271,419 toArzonico et al.; U.S. Pat. No. 5,220,930 to Gentry; U.S. Pat. No.6,908,874 to Woodhead et al.; U.S. Pat. No. 6,929,013 to Ashcraft etal.; U.S. Pat. No. 7,195,019 to Hancock et al.; U.S. Pat. No. 7,276,120to Holmes; U.S. Pat. No. 7,275,548 to Hancock et al.; PCT WO 01/08514 toFournier et al.; and PCT WO 03/043450 to Hajaligol et al., thedisclosures of which are incorporated herein by reference in theirentireties. Representative wrapping materials are commercially availableas R. J. Reynolds Tobacco Company Grades 119, 170, 419, 453, 454, 456,465, 466, 490, 525, 535, 557, 652, 664, 672, 676 and 680 fromSchweitzer-Mauduit International.

To maximize aerosol and flavor delivery which otherwise can be dilutedby radial (i.e., outside) air infiltration through the shell 15, one ormore layers of non-porous cigarette paper can be used to envelop thearticle (with or without the overwrap present). Examples of suitablenon-porous cigarette papers are commercially available fromKimberly-Clark Corp. as KC-63-5, P878-5, P878-16-2 and 780-63-5.Preferably, the overwrap is a material that is substantially impermeableto the vapor formed during use of the inventive article. If desired, theoverwrap (or the shell if the overwrap is absent) can comprise aresilient paperboard material, foil-lined paperboard, metal, polymericmaterials, foams, nanofiber webs, or the like, and this material can becircumscribed by a cigarette paper wrap. Moreover, the article 10 caninclude a tipping paper that circumscribes the article and optionallycan be used to attach a filter material to the article.

The shell 15, when formed of a single layer, can have a thickness ofabout 0.2 mm to about 3.0 mm, about 0.3 mm to about 2.0 mm, about 0.4 mmto about 1.5 mm, or about 0.5 mm to about 1.25 mm. The addition offurther layers, as discussed above, can add to the thickness of theshell. Further exemplary types of components and materials that can beused to provide the functions described above or be used as alternativesto the materials and components noted above can be those of the typesset forth in US Pub. No. 2010/00186757 to Crooks et al. and US Pub. No.2011/0041861 to Sebastian et al., the disclosures of which areincorporated herein by reference in their entireties.

As seen in the embodiment of FIG. 1, the smoking article 10 includes anelectronic control component 20, a flow sensor 30, and a battery 40, andthese components can be placed in a variety of orders within thearticle. Although not expressly shown, it is understood that the article10 can include wiring as necessary to provide power from the battery 40to the further components and to interconnect the components forappropriate operation of the necessary functions provided by thearticle. The article 10 further includes a resistive heating element 50as described herein. In the illustrated embodiment, the resistiveheating element 50 is a metal coil that can be electrically connected tothe battery 40 through appropriate wiring of the terminals 51 tofacilitate formation of a closed electrical circuit with current flowingthrough the heating element. Further wiring (not illustrated) can beincluded to provide the necessary electrical connections within thearticle. In specific embodiments, the article 10 can be wired with anelectrical circuit such that the control component 20 delivers,controls, or otherwise modulates power from the battery 40 forenergizing the resistive heating element 50 according to one or moredefined algorithms, including pulse width modulation, such as alreadydescribed above. Such electrical circuit can specifically incorporatethe flow sensor 30 such that the article 10 is only active at times ofuse by the consumer. For example, when a consumer puffs on the article10, the flow sensor detects the puff, and the control component 20 isthen activated to direct power through the article such that theresistive heating element 50 produces heat and thus provides aerosol forinhalation by the consumer. The control algorithm can call for power tothe resistive heating element 50 to cycle and thus maintain a definedtemperature. The control algorithm therefore can be programmed toautomatically deactivate the article 10 and discontinue power flowthrough the article after a defined time lapse without a puff by aconsumer. Moreover, the article can include a temperature sensor toprovide feedback to the control component. Such sensor can be, forexample, in direct contact with the resistive heating element 50.Alternative temperature sensing means likewise can be used, such asrelying upon logic control components to evaluate resistance through theresistive heating element and correlate such resistance to thetemperature of the element. In other embodiments, the flow sensor 30 canbe replaced by appropriate components to provide alternative sensingmeans, such as capacitive sensing, as otherwise described herein. Anyvariety of sensors and combinations thereof can be incorporated, asalready described herein. Still further, one or more control buttons 16can be included to allow for manual actuation by a consumer to elicit avariety of functions, such as powering the article 10 on and off,turning on the heating element 50 to generate a vapor or aerosol forinhalation, or the like.

Additionally, the article can include one or more status indicators 19positioned on the shell 15. Such indicators, as discussed above, canshow the number of puffs taken or remaining from the article, can beindicative of an active or inactive status, can light up in response toa puff, or the like. Although six indicators are illustrated, more orfewer indicators can be present, and the indicators can take ondifferent shapes and orientations and can even be simply an opening inthe shell (such as for release of sound when such indicators arepresent).

As illustrated in the embodiment of FIG. 1, a reservoir bottle 205 isshown in proximity to the heating element 50, and a transport element300 (a wick in this embodiment) extends from the reservoir bottle 205and into the coil of the resistive heating element 50. The reservoirbottle is one embodiment illustrating means of storing an aerosolprecursor composition. The wick utilizes capillary action to draw theaerosol precursor composition from the reservoir bottle and into anaerosolization zone 400 defined by the area in and around the resistiveheating element 50 in the form of a metal wire coil. As such, heatproduced by the resistive heating element causes the aerosol precursorcomposition to aerosolize in the space around the resistive heatingelement (i.e., the aerosolization zone). The formed aerosol is thendrawn by a user through the mouthend 11 of the smoking article 10. Asthe aerosol precursor composition in the aerosolization zone isaerosolized by the heating of the resistive heating element, furtheraerosol precursor composition is wicked out of the reservoir bottle 205to the aerosolization zone for aerosolization. The cycle continues untilsubstantially all of the aerosol precursor composition has beenaerosolized.

As seen in the embodiment of FIG. 1, the mouthend 11 of the article 10is substantially an open cavity with the resistive heating element 50and the reservoir bottle 205 disposed therein. Such open cavity providesa volume for release of the aerosol from the transport element 300 as itis withdrawn from the reservoir and heated by the resistive heatingelement. The article also includes a mouth opening 18 in the mouthend 11to allow for withdrawal of the aerosol from the cavity around theresistive heating element 50. Although not expressly shown in theillustration of FIG. 1, the article can include a filter material (suchas cellulose acetate or polypropylene) in the mouthend thereof toincrease the structural integrity thereof and/or to provide filteringcapacity, if desired, and/or to provide resistance to draw. For example,an article according to the invention can exhibit a pressure drop ofabout 50 to about 250 mm water pressure drop at 17.5 cc/second air flow.In further embodiments, pressure drop can be about 60 mm to about 180 mmor about 70 mm to about 150 mm. Pressure drop value can be measuredusing a Filtrona Filter Test Station (CTS Series) available fromFiltrona Instruments and Automation Ltd or a Quality Test Module (QTM)available from the Cerulean Division of Molins, PLC. To facilitate airflow through the article, an air intake 17 can be provided and cansubstantially comprise an aperture in the shell 15 that allows for airflow into the interior of the article. A plurality of air intakes can beprovided, and the air intakes can be positioned at any location upstreamfrom the mouthend of the article such that air from the air intake canmingle with and facilitate removal of the formed aerosol from the cavityaround the resistive heating element and through the opening in themouthend of the article. Although not illustrated, if desired,structural elements can be provided within the article so as toeffectively isolate one or more components within the article from theair flowing from the air intake to the opening in the mouthend. In otherwords, a defined air flow path can be provided, and such defined airflow path can substantially avoid air flowing through the air flow pathfrom coming into physical contact with one or both of the battery 40 andthe control component 20. As illustrated in FIG. 1, air taken in throughthe air intake 17 passes the flow sensor 30 before entering the cavitysurrounding the heating element such that activation of the flow sensorwill facilitate heating of the heating element, as otherwise describedherein.

In the embodiment shown in FIG. 2, the aerosol precursor composition isstored in a reservoir layer 200, which can be a layer of porous materialthat is at least partially saturated with the aerosol precursorcomposition. In such embodiments, the cavity in the mouthend 11 of thearticle 10 can be significantly reduced. As seen in FIG. 2, an aerosolpassage tube 250 is positioned downstream from the resistive heatingelement 50 coiled around the transport element 300. Aerosol formed byheating of the aerosol precursor composition in the transport element bythe resistive heating element can be drawn by a user through an aerosolpassage 260 defined by the aerosol passage tube.

In preferred embodiments, the article 10 can take on a size that iscomparative to a cigarette or cigar shape. Thus, the article can have adiameter of about 5 mm to about 25 mm, about 5 mm to about 20 mm, about6 mm to about 15 mm, or about 6 mm to about 10 mm. Such dimension canparticularly correspond to the outer diameter of the shell 15.

The smoking article 10 in the embodiment illustrated in FIG. 1 can becharacterized as a disposable article. Accordingly, it can be desirablefor the reservoir containing the aerosol precursor composition in suchembodiments to include a sufficient amount of aerosol precursorcomposition so that a consumer can obtain more than a single use of thearticle. For example, the article can include sufficient aerosolizableand/or inhalable materials such that the article can provide a number ofpuffs substantially equivalent to the number of puffs (each of about twoto four seconds duration) available from a plurality of conventionalcigarettes—e.g., 2 or more, 5 or more, 10 or more, or 20 or moreconventional cigarettes. More particularly, a disposable, single unitarticle according to the embodiment of FIG. 1 can provide about 20 ormore, about 50 or more, or about 100 or more puffs, a single puff beingmeasured as already described herein.

In particularly preferred embodiments an article according to theinvention can comprise two units that are attachable and detachable fromeach other. For example, FIG. 3 shows a smoking article 10 according toone embodiment that is formed of a control body 80 and a cartridge 90.In specific embodiments, the control body can be referred to as beingreusable, and the cartridge can be referred to as being disposable. Insome embodiments, the entire article can be characterized as beingdisposable in that the control body can be configured for only a limitednumber of uses (e.g., until a battery power component no longer providessufficient power to the article) with a limited number of cartridgesand, thereafter, the entire article 10, including the control body, canbe discarded. In other embodiments, the control body can have areplaceable battery such that the control body can be reused through anumber of battery exchanges and with many cartridges. Similarly, thearticle 10 can be rechargeable and thus can be combined with any type ofrecharging technology, including connection to a typical electricaloutlet, connection to a car charger (i.e., cigarette lighterreceptacle), and connection to a computer, such as through a USB cable.

The control body 80 and the cartridge 90 are specifically configured soas to engage one another and form an interconnected, functioning device.As illustrated in FIG. 3, the control body 80 includes a proximalattachment end 13 that includes a projection 82 having a reduceddiameter in relation to the control body. The cartridge includes adistal attachment end 14 that engages the proximal engagement end of thecontrol body 80 to provide the smoking article 10 in a functioning,usable form. In FIG. 3, the control body projection 82 includes threadsthat allow the cartridge 90 to screw onto the control body 80 viacorresponding threads (not visible in FIG. 3) in the distal attachmentend of the cartridge. Thus, the distal attachment end of the cartridge90 can include an open cavity for receiving the control body projection82. Although a threaded engagement is illustrated in FIG. 3, it isunderstood that further means of engagement are encompassed, such as apress-fit engagement, a magnetic engagement, or the like.

The functioning relationship between the control body 80 and thecartridge 90 is further seen in FIG. 4, which shows the two detachedunits in cross section. The control body 80 includes the controlcomponent 20, flow sensor 30, and battery 40. Although these componentsare illustrated in a specific alignment, it is understood that variousalignments of the components are encompassed by the invention. Thecontrol body 80 further includes a plurality of indicators 19 and an airintake 17 in the control body shell 81. Various positions for one ormore air intakes are encompassed by the invention. As shown, the airintake 17 is positioned such that air drawn through the intakesufficiently contacts the flow sensor 30 to activate the sensor(although other positions are encompassed, particularly if differentsensing means are provided or if manual actuation, such as with a pushbutton, is provided). The shell 81 can be formed of materials alreadydescribed herein in relation to the embodiment of FIG. 1. A receptacle60 also is included at the proximal attachment end 13 of the controlbody 80 and extends into the control body projection 82 to allow forease of electrical connection with the resistive heating element 50 whenthe cartridge 90 is attached to the control body. In the illustratedembodiment, the receptacle 60 includes a central open passage tofacilitate air flow from the air intake in the control body into thecartridge during use of the article 10.

The cartridge 90 includes a cartridge shell 91 with a mouth opening 18at the mouthend 11 thereof to allow passage of air and entrained vapor(i.e., the components of the aerosol precursor composition in aninhalable form) from the cartridge to a consumer during draw on thearticle 10. The cartridge shell 91 (and an optional insulator layerand/or filter) can be formed of materials as already described herein asbeing useful for such purpose. The cartridge 90 further includes aresistive heating element 50 in the form of a metal wire coil. Theresistive heating element includes terminals 51 (e.g., positive andnegative terminals) at the opposing ends thereof for facilitatingcurrent flow through the resistive heating element and for attachment ofthe appropriate wiring (not illustrated) to form an electricalconnection of the resistive heating element with the battery 40 when thecartridge 90 is connected to the control body 80. Specifically, a plug65 is positioned at the distal attachment end 14 of the cartridge. Whenthe cartridge 90 is connected to the control body 80, the plug 65engages the receptacle 60 to form an electrical connection such thatcurrent controllably flows from the battery 40, through the receptacleand plug, and to the resistive heating element 50. The cartridge shell91 can continue across the distal attachment end such that this end ofthe cartridge is substantially closed with the plug protrudingtherefrom. As illustrated in FIG. 4, the plug 65 includes an opencentral passage that aligns with the open central passage in thereceptacle 60 to allow air to flow from the control body 80 and into thecartridge 90.

Generally, in use, when a consumer draws on the mouthend 11 of thecartridge, the flow sensor 30 detects the change in flow and activatesthe control component 20 to facilitate current flow through theresistive heating element 50. Thus, it is useful for air flow to travelthrough the control body 80 in a manner that flow sensor 30 detects airflow almost instantaneously. When the flow sensor 30 is positionedwithin the control body 80, it can be useful to have an air intake 17 onthe control body. If desired, a sealed flow path can be provided suchthat the flow sensor 30 within the control body 80 is in fluidconnection with the cartridge interior after the cartridge and thecontrol body are engaged, such fluid connection being sealed withrespect to the remainder of the components within the control body butopening into the cartridge 90 when attached to the control body.Further, in other embodiments, the flow sensor 30 can be located withinthe cartridge 90 instead of the control body 80.

In the embodiment illustrated in FIG. 4, two separate reservoirs and twoseparate transport elements are shown. A reservoir for use according tothe present invention can be any component that functions to store andrelease one or more components of the aerosol precursor composition. Insome embodiments, such as illustrated in FIG. 1, the reservoir can be acontainer, such as a bottle, in which the aerosol precursor compositionis stored. The container can be substantially impermeable in relation tothe aerosol precursor such that the material cannot escape through thewalls of the container. In such embodiments, an opening can be providedfor passage of the aerosol precursor composition therefrom. For example,in FIG. 1, a transport element 300 (e.g., a wick) is shown filling anopening in the reservoir bottle 205. The term “bottle” is meant togenerally encompass any container having walls and at least one opening.The aerosol precursor composition in the reservoir bottle thus moves outof the bottle by capillary action via the wick. Other systems forpassage of the aerosol precursor composition from a reservoir bottle arealso encompassed by the invention. For example, a tube or other conduitcan be used for passage of the aerosol precursor composition out of thebottle and through the tube or other conduit. Alternately, passive oractive flow of the liquid from the bottle can be controlled with anappropriate valve mechanism that can be opened to allow flow of theaerosol precursor composition when the smoking article is in use and toprevent flow of the aerosol precursor composition when the smokingarticle is not in use. Active flow mechanisms incorporating micro-pumpdevices are envisioned for use according to the present invention. Suchcontainer can be formed of any suitable material that is notsubstantially reactive with any components of the aerosol precursorcomposition, such as glass, metal, low- or no-porosity ceramics,plastics, and the like.

In some embodiments, a reservoir can be a container that is providedwithout an opening, but a portion or all of the walls of the containercan be porous and thus allow permeation of the aerosol precursorcomposition out of the container through the walls thereof. For example,porous ceramics can be useful in such regard. Any other material ofsuitable porosity likewise could be used. In such embodiments, at leasta portion of the porous container can be in contact with the resistiveheating element such that aerosol precursor composition exiting thebottle can be vaporized by the heater. Alternately, a further transportelement can be in contact with the porous bottle to transport theaerosol precursor composition from the container and to the heater.

In particular embodiments, a reservoir can be a woven or non-wovenfabric or another mass of fibers suitable for retaining the aerosolprecursor composition (e.g., through absorption, adsorption, or thelike) and allowing wicking away of the precursor composition fortransport to the aerosolization zone. For example, FIG. 4 illustrates afirst reservoir layer 201 and a second reservoir layer 202, eachretaining one or more components of the aerosol precursor composition.In each case, the reservoir layer is essentially a non-woven layer offibers rolled into the form of a tube that lines a portion of the innersurface of the cartridge shell 91. Such reservoir layers can be formedof natural fibers, synthetic fibers, or combinations thereof.Non-limiting examples of useful materials include cotton, cellulose,polyesters, polyamides, polylactic acids, combinations thereof, and thelike. Similarly, reservoir layers can be formed of ceramics or otherporous material that retains (i.e., can be at least partially saturatedwith) a liquid composition combined therewith. A smoking articleaccording to the present invention can include one reservoir or aplurality of reservoirs (e.g., two reservoirs, three reservoirs, fourreservoirs, or even more).

A transport element for use according to the present invention can beany component that functions to transport one or more components of anaerosol precursor composition from a reservoir to an aerosolization zonein the smoking article where a resistive heating element aerosolizes theaerosol precursor composition and thus form an aerosol. A transportelement particularly can be a wick that utilizes capillary action in thetransport of liquids. A wick for use according to the invention thus canbe any material that provides sufficient wicking action to transport oneor more components of the aerosol precursor composition to theaerosolization zone. Non-limiting examples include natural and syntheticfibers, such as cotton, cellulose, polyesters, polyamides, polylacticacids, glass fibers, combinations thereof, and the like. Other exemplarymaterials that can be used in wicks include metals, ceramics, andcarbonized materials (e.g., a foam or monolith formed of a carbonaceousmaterial that has undergone calcining to drive off non-carbon componentsof the material). Wicks further can be coated with materials that alterthe capillary action of the fibers, and the fibers used in forming wickscan have specific cross-sectional shape and can be grooved so as toalter the capillary action of the fibers. For example, temperatureadaptive polymers can be used. Such adaptive polymers can be coated onfibers or used in other manners, and these polymers are effective forproviding altered liquid transport characteristics based on thesurrounding conditions. Temperature adaptive polymers particularly canexhibit low transport at reduced temperatures and can exhibit increasedtransport at increased temperatures. One example is a material known asAdaptive by HeiQ®. Fibers used in forming wicks can be provided singly,bundled, as a woven fabric (including meshes and braids), or as anon-woven fabric. Porosity of the wick material also can be controlledto alter the capillary action of the wick, including controlling averagepore size and total porosity. Separate wicks also can have differentlengths. The term “wick” is also intended to encompass capillary tubes,and any combination of elements providing the desired capillary actioncan be used.

While the use of wicks is known, the art has not heretofore recognizedthe drawbacks that can impede the quality of an aerosol that isgenerated when an aerosol precursor composition is wicked to a heaterfor aerosolization. For example, the separate components of an aerosolprecursor composition can each transport at different rates along asingle wick formed of a specific material. Thus, the ratio of thecomponents at the heater can be different than the ratio of thecomponents in the original aerosol precursor composition since onecomponent can wick to the heater faster or slower than the othercomponents of the aerosol precursor composition. Likewise, separatecomponents of the aerosol precursor composition can exhibit differentaerosolization characteristics (e.g., rate of aerosolization ortemperature at which aerosolization takes place). When the aerosolprecursor composition is exposed to a substantially uniform temperature(or thermal energy input) at the resistive heater element, the separatecomponents of the aerosol precursor composition can aerosolizedifferently such that a uniform aerosol composition is not achieved ineach puff on the article. For example, early puffs on the article can beunintentionally enriched in the components of the aerosol precursorcomposition that have the lowest temperature of vaporization. It istherefore desirable, such as provided according to the presentdisclosure, to have a transporting/heating system that can transport andheat the various chemical components of the aerosol precursorcomposition at a controlled rate so as to achieve a uniform puffchemistry.

The smoking articles described herein provide for generation of aerosolsof desired composition by controlling the rate of transport and heatingof the components of an aerosol precursor composition. Such smokingarticles generally can comprise an aerosolization zone that includes atleast one resistive heating element. The aerosolization zone can bedefined as an area wherein the aerosol precursor composition is incontact with the resistive heating element or is sufficiently inproximity to the resistive heating element such that heat generated bythe resistive heating element causes the aerosol precursor compositionto vaporize for aerosol formation. An aerosolization zone can be an areawhere one or more transport elements are spatially aligned with one ormore resistive heating elements such that liquid components transportedby the one or more transport elements are heated by the one or moreresistive heating elements so as to vaporize and form an aerosol.

A smoking article according to the present invention also generallycomprises an electrical power source that is in electrical connectionwith at least one resistive heating element. Various control elementsalso can be included, as already discussed above.

Still further, the smoking article includes an aerosol precursorcomposition, which can comprise a variety of components, as discussedabove. Typically, the aerosol precursor composition will be formed of afirst component and at least a second component. Thus, the aerosolprecursor composition can be formed of a plurality of components. Theaerosol precursor composition is provided in the smoking article so asto be in fluid communication with the aerosolization zone such that theaerosol precursor composition is transported from a storagecomponent—i.e., one or more reservoirs—to the aerosolization zone. Suchtransport can particularly be via capillary action, more particularlyalong a wick or similar component. At least two separate components ofthe aerosol precursor composition preferably are separately transportedto the aerosolization zone. Such separate transport can mean that theentire content of at least one component of the aerosol precursorcomposition is transported via means (e.g., a wick) by which at leastone other component of the aerosol precursor composition is nottransported. Separate transport can apply in this regard to eachindividual component of the aerosol precursor composition or anycombination of the individual components. For example, in a fourcomponent aerosol precursor composition, component 1 can be transportedby a first transport element and components 2, 3, and 4 can betransported by a second transport element. Alternately, components 1 and2 can be transported by a first transport element and components 3 and 4can be transported by a second transport element. Likewise, component 1can be transported by a first transport element, component 2 can betransported by a second transport element, and components 3 and 4 can betransported by a third transport element. Still further, component 1 canbe transported by a first transport element, component 2 can betransported by a second transport element, component 3 can betransported by a third transport element, and component 4 can betransported by a fourth transport element. Separate transport, in otherembodiments, can mean that a majority of at least one compound use inthe aerosol precursor composition is transported via means through whicha majority of at least one different compound in the aerosol precursoris not transported. In such embodiments, separate transport can bedefined in that greater than 50%, greater than 60%, greater than 70%,greater than 80%, greater than 90%, or greater than 95% by weight of theindividual compound in the aerosol precursor composition is transportedby the individual transport element. In specific embodiments, separatetransport can mean that 100% by weight of the individual compound in theaerosol precursor composition is transported by the individual transportelement. Similarly, separate transport can encompass transport of thesame compound in two or more different transport elements so long aseach different transport element transports different ratios of thecompounds. Moreover, in some embodiments, each separate componentforming the aerosol precursor composition can be formed of only a singlecompound. Likewise, the separate components can be expressly differentin that there is no overlap of compounds between the separatecomponents.

In addition to the foregoing, separate transport does not necessitateseparate transport along the entire route. For example, component 1 ofan aerosol precursor composition can be stored in reservoir 1 andtransported by transport element 1, and component 2 of the aerosolprecursor composition can be stored in reservoir 2 and transported bytransport element 2. At some point prior to entering the aerosolizationzone (or more particularly, prior to contacting the resistive heatingelement), the two separate transport element can be combined or mergeinto a single transport element to simplify heating. Since the separatecomponents were transported at least partially from the reservoir to theaerosolization zone via separate transport elements, the transport ofthe components can be considered to be separate. For example, when wicksare used, the separate wicks can be bundled in the aerosolization zone.

Various combinations of one or more reservoirs, one or more transportelements, and one or more heaters, all having various designs and formedof various materials, can be used to achieve controlled rate oftransport and heating of the aerosol precursor composition components asdiscussed herein. In one embodiment, a single reservoir can be used forstorage of the aerosol precursor composition, and a plurality oftransport elements can be used for transport of the components of theaerosol precursor composition to the aerosolization zone. For example,the multiple separate components of the aerosol precursor compositioncan be physically separated in the reservoir (e.g., a reservoir bottlewith multiple compartments) so as to be in two or more separatecompartments, and two or more transport elements (e.g., a separatetransport element for each compartment) can be used to transport therespective components from the compartments to the aerosolization zone.

The transport element used to transport a component (or a group of twoor more components) of the aerosol precursor composition can be designedto accommodate particular characteristics of the component to betransported. For example, in relation to wicks, for a component that canwick at a slower rate than other components of the aerosol precursorcomposition, the wick for the slower wicking component can be designedto elicit increased wicking rate. The present invention encompasses avariety of wick designs (or combinations of different types of transportelements) that can be useful to provide customizable transportcharacteristics that can be applied for use with specific components ofan aerosol precursor composition to achieve a consistent andreproducible aerosol.

In some embodiments where wicking is used, the wick cross-section can bedesigned to achieve the desired result. Typical fibers have asubstantially round cross-section, and altering fiber cross-sectionshape can increase the surface area per denier of the fiber and thusimproving wicking along the fiber. For example, a fiber can be formedwith longitudinal grooves that are intended to facilitate wicking, suchas a 4DG fiber (available from Fiber Innovation Technology) and winged(available from Alasso Industries). Fibers formed with an “X” or “Y”shaped cross-section also can provide for controlled wicking.

Wicking properties of fibers also can be altered via physicalmodification of a formed fiber. For example, fibers can be scored orpartially cut along the length thereof so as to increase the overallexposed surface area of the fiber. Such scores or cuts can be made atany angle greater than 0° and less than 180° relative to the axis of thefiber.

In other embodiments, at least a portion of a fiber utilized in a wickcan be designed to promote radial wicking. Continuous filament fibers,such as fiberglass, tend to promote wicking primarily along the axis ofthe filament—i.e., axial wicking. Through appropriate design, thefilament also can be caused to promote radial wicking—i.e., outward fromthe axis of the filament. For example, radial wicking can be facilitatedthrough wick construction with randomly oriented fiber or withfibrillation of the fiber surface. Such design particularly can beuseful in the area of the filaments that are in proximity to or incontact with the heater as it can cause more of the precursorcomposition to be available for aerosolization in the specific area ofthe heater. A similar effect can be achieved such as through the use ofparticles or beads that can be sintered or otherwise interconnected toprovide a continuous wick structure.

Further, the fibers of the wick material can be treated or coated toincrease (or decrease, if desired) the wicking action of a fiber. Also,fiber material selection can be utilized to increase or decrease wickingaction and thus control the wicking rate of a specific component of theaerosol precursor composition. Wicking also can be customized throughchoice of the dimensions of the fibers used in the wicks and the overalldimensions of the wick, including wick length and wick diameter.

The type of material used to form individual wicks also can becustomized to transport specific types of compounds. For example, one ormore wicks can be formed of hydrophobic materials so as topreferentially wick hydrophobic liquids. Further, one or more wicks canbe formed of hydrophilic materials so as to preferentially wickhydrophilic liquids. Moreover, one or more wicks can be formed ofmaterials that are neither hydrophilic nor hydrophobic, such as naturalmaterials, so as to preferentially wick liquids that are neithersignificantly polar nor significantly non-polar.

In some embodiments, a wick can interact with a heater such that theheater essentially surrounds a portion of the wick. For example, as seenin the embodiment of FIG. 1, the heater is a wire coiled around thewick. In other embodiments, at least a portion of the heater can bewithin the wick. For example, a braided fiber sleeve can be used as thewick with a resistive heating element wire coil positioned inside thesleeve. Similarly, a heater wire can be embedded within a porous wickingstructure or included within a woven or non-woven fabric.

Thus, a wick (or other transport element) can be matched to thecomponent or group of components to achieve a desired transport ratebased upon data showing the transport rate of the individual componentswith the chosen transport element. In this manner, through choice ofappropriate transport element, the individual components of the aerosolprecursor can be transported to the aerosolization zone at asubstantially similar rate so that the composition of the formed aerosolmore closely and consistently matches the original composition of theaerosol precursor composition as desired. Depending upon the componentsused in the aerosol precursor composition, transport element designs canbe chosen to preferentially withdraw specific components from a commonreservoir. Thus, a single reservoir containing the aerosol precursorcomposition can utilize two or more transport elements of differentdesign so that one or more components of the aerosol precursorcomposition preferentially transports along one transport element andone or more separate components of the aerosol precursor compositionpreferentially transports along one or more different transportelements.

In certain embodiments, controlling transport of the separate componentsof the aerosol precursor composition particularly can be facilitatedthrough utilization of a plurality of reservoirs, each reservoirutilizing a separate transport element to transport the components ofthe aerosol precursor composition to the aerosolization zone. One suchexample is shown in FIG. 4. As seen therein, the cartridge 90 includes afirst reservoir layer 201 and a second reservoir layer 202, which areeach layers of nonwoven fibers formed into the shape of a tubeencircling the interior of the cartridge shell 91, in this embodiment.The first reservoir layer 201 includes at least one component of theaerosol precursor composition, and the second reservoir layer 202includes at least one separate component of the aerosol precursorcomposition. The liquid components, for example, can be sorptivelyretained by the reservoir layers. In one embodiment, first reservoirlayer 201 can include a polyol, such as glycerol, and a furthercomponent, such as nicotine, and second reservoir 202 can include adifferent polyol, such as propylene glycol. The first reservoir layer201 is in fluid connection with a first transport element 301 (a wick inthis embodiment), and the second reservoir layer 202 is in fluidconnection with a second transport element 302 (a wick in thisembodiment). The first wick 301 and the second wick 302 separatelytransport the components of the aerosol precursor composition stored inthe respective reservoir layers via capillary action to theaerosolization zone 400 of the cartridge 90. As illustrated, the firstwick 301 and the second wick 302 essentially merge in the aerosolizationzone 400 to form a single wick that this in direct contact with theresistive heating element 50 that is in the form of a metal wire coil inthis embodiment. As discussed herein, the wicks can be of the samedesign, or each wick can have a different design or construction (i.e.,a different cross-sectional shape; a different type of fiber; adifferent type of material; have a different surface treatment or lackthereof, such as coatings or scoring of fibers; be woven or non-woven;include more or less fibers; include fibers of different dimensions; orhave overall different dimensions). Use of separate wicks thus allowsfor customization of wicking of the separate components of the aerosolprecursor composition, such as varying the wicking rate of specificcomponents or varying the overall amounts of specific components thatare wicked to the aerosolization zone.

In use, when a user draws on the article 10, the resistive heatingelement 50 is activated (e.g., such as via a puff sensor), and thecomponents for the aerosol precursor composition are vaporized in theaerosolization zone 400. Drawing upon the mouthend 11 of the article 10causes ambient air to enter the air intake 17 and pass through thecentral opening in the receptacle 60 and the central opening in the plug65. In the cartridge 90, the drawn air passes through an air passage 230in an air passage tube 220 and combines with the formed vapor in theaerosolization zone 400 to form an aerosol. The aerosol is whisked awayfrom the aerosolization zone, passes through an air passage 260 in anair passage tube 250, and out the mouth opening 18 in the mouthend 11 ofthe article 10. After vaporization of the aerosol precursor compositionin the aerosolization zone, further amounts of the separate componentsof the aerosol precursor composition transport along the wicks to theaerosolization zone via capillary action to at least partially saturatethe wick in the aerosolization zone so additional aerosol can be formedwhen the user makes a further draw on the article. Of course, suchexemplary embodiments should not be viewed as limiting the scope of thedisclosure, and other conformations or components can be utilized toachieve the same function of forming an improved aerosol that is drawnfrom the article into the mouth of a user.

Although FIG. 4 illustrates the use of two separate reservoirs and twoseparate transport elements, the invention is not so limited. Rather,the number of reservoirs and transport elements used can vary dependingupon the number of components used in the aerosol precursor compositionand the need to separately transport the individual components toachieve a defined aerosol composition. Thus, a single reservoir can beused with a plurality of transport elements such that two or morecomponents of the aerosol precursor stored in the single reservoir areseparately transported from the reservoir to the aerosolization zone.Likewise, a plurality of reservoirs can be combined with a plurality oftransport elements such that a plurality of separate components storedin the separate reservoirs are separately transported from thereservoirs to the aerosolization zone. This can include one, two, three,four, five, or even more reservoirs in combination with two, three,four, five, or even more transport elements.

Utilizing separate transport elements to transport separate componentsof the aerosol precursor composition can be useful to normalize thetransport rate of the individual components to the aerosolization zone.For example, in the case of wicking, if one component is found to wickslower than the further components, the slower wicking component can bestored in a separate reservoir and transported to the aerosolizationzone using a wick that is designed to increase the wicking rate of thecomponent. In this manner, the wicking rates of the individualcomponents can be normalized such that the wicking rates of thecomponents of the aerosol precursor composition along their respectivewicks each differ by about 25% or less, about 20% or less, about 15% orless, about 10% or less, or about 5% or less. Combinations of differenttypes of transport elements also can be used to customize the transportrate of the various components of the aerosol precursor composition.

In addition to the use of a plurality of reservoirs and transportelements, a smoking article according to the present disclosure also canutilize a plurality of resistive heating elements. For example, FIG. 5shows a cross-section of a cartridge 90 that is substantially identicalto the cartridge of FIG. 4 except that two resistive heating elements(55, 56) are used to form aerosol by separately heating two or morecomponents of the aerosol precursor composition. More particularly,visible in the illustration of this embodiment of a smoking article 10is a shell 15, an aerosol passage tube 250 defining an aerosol passage260, and a reservoir layer 202 positioned between the aerosol passagetube and the shell. Visible through the aerosol passage is a firsttransport element 301 that is in fluid communication with a firstreservoir layer (not visible) and a second transport element 302 that isin fluid communication with the second reservoir layer 202. The firsttransport element 301 is in contact with a first resistive heatingelement 55 in the aerosolization zone 400, and the second transportelement 302 is in contact with a second resistive heating element 56also in the aerosolization zone. The first transport element transportsa first component of the aerosol precursor composition from the firstreservoir layer to the first resistive heating element, and the secondtransport element transports a second component of the aerosol precursorcomposition from the second reservoir layer to the second resistiveheating element. In this way, the separate components transported to theseparate heating elements can be heated to different temperatures toprovide a more consistent aerosol for draw by a user. Further, the useof multiple heaters can allow for the use of smaller individual heaters,can allow for the use of smaller transport element being heated by theindividual heaters, and can reduce the amount of electrical energy thatis required by each heater to form the aerosol. The use of individualheaters likewise can allow for customized energy flow to each heater sothat only the amount of electrical energy required to vaporize thespecific component or components of the aerosol precursor compositiondelivered to that specific heater is delivered. The aerosolizationtemperature of the separate heaters can be substantially the same or canbe different. In some embodiments, the aerosolization temperature of theseparate heaters can differ by 2° C. or greater, 5° C. or greater, 10°C. or greater, 20° C. or greater, 30° C. or greater, or 50° C. orgreater. When three or more heaters are used, fewer than all of theheaters can utilize aerosolization temperatures that are substantiallythe same. For example, when three heaters are used, the temperature ofheaters 1 and 2 can be substantially the same, and the temperature ofheater 3 can be different.

As noted previously, a smoking article according to the presentdisclosure is not limited to the use of only one or only two heatingelements. Rather, the smoking article can include any number of heatingelements up to the number of individual components forming the aerosolprecursor composition.

In addition to the foregoing, the control body and cartridge can becharacterized in relation to overall length. For example, the controlbody can have a length of about 50 mm to about 110 mm, about 60 mm toabout 100 mm, or about 65 mm to about 95 mm. The cartridge can have alength of about 20 mm to about 60 mm, about 25 mm to about 55 mm, orabout 30 mm to about 50 mm. The overall length of the combined cartridgeand control body (or the overall length of a smoking article accordingto the invention formed of a single, unitary shell) can be approximatelyequal to or less than the length of a typical cigarette—e.g., about 70mm to about 130 mm, about 80 mm to about 125 mm, or about 90 mm to about120 mm.

Although the cartridge and the control body can be provided together asa complete smoking article or medicament delivery article generally, thecomponents also can be provided separately. For example, the inventionalso encompasses a disposable unit for use with a reusable smokingarticle or a reusable medicament delivery article.

In specific embodiments, a disposable unit or cartridge according to theinvention can be substantially identical to a cartridge as describedabove in relation to the appended figures. Thus, a disposable cartridgecan comprise a substantially tubular shaped cartridge shell having adistal attachment end configured to engage a reusable smoking article ormedicament delivery article and an opposing mouthend configured to allowpassage of a formed vapor and any further inhalable materials to aconsumer. The cartridge shell can define an interior cartridge spacethat includes additional cartridge components. Specifically, theinterior cartridge space can include one or more reservoirs for storinga plurality of components of an aerosol precursor composition, one ormore heaters positioned within a aerosolization zone for vaporizing theaerosol precursor composition, and a plurality of transport elementsthat transport the components of the aerosol precursor composition fromthe reservoir(s) to the heater(s), which can be described as being influid communication with each other. The inner surface of the cartridgeshell can include an insulator layer thereon, and remaining componentsof the cartridge can be positioned within the interior cartridge spaceinterior to the insulator layer. Optionally, one or more reservoirs canbe provided as one or more layers of porous material that can functionas the insulator layer as well as the reservoir. The cartridge caninclude further hardware (e.g., electrical wiring, electrical terminals,electrical contacts, etc) to facilitate current flow through theresistive heating element(s). Such further hardware can be used toprovide an exterior electrical connection—i.e., means for forming anelectrical connection to a power source when the disposable cartridge isengaged to a reusable control body. For example, the disposablecartridge can include an electrical plug projecting from the distalattachment end of the cartridge that can engage a receptacle in acontrol body. The disposable cartridge also can include attachmentmeans, such as threads, beads, or the like to facilitate a mechanicalconnection with a control body.

In addition to the disposable unit, the invention further can becharacterized as providing a separate control body for use in a reusablesmoking article or a reusable medicament delivery article. In specificembodiments, the control body can generally be formed of a shell havinga proximal attachment end (which can include one or more aperturestherein) for receiving an attachment end of a separately providedcartridge. The control body further can include a power source (i.e., anelectrical power source) that can be in electrical connection with oneor more additional components of the control body, including componentsthat facilitate electrical connection with a separately providedcartridge. The control body also can include further components,including components for actuating current flow into a heating member,and components for regulating such current flow to maintain a desiredtemperature for a desired time and/or to cycle current flow or stopcurrent flow when a desired temperature has been reached or the heatingmember has been heating for a desired length of time. Thus, the controlbody can include a flow sensor and further control components. Thecontrol body further can comprise one or more pushbuttons associatedwith one or both of the components for actuating current flow. Thecontrol unit even further can comprise indicators, such as lightsindicating the heater is heating and/or indicating the number of puffsremaining for a cartridge that is used with the control unit. Thecontrol body also can include attachment means, such as threads, beads,or the like to facilitate a mechanical connection with a cartridge.

Although the various figures described herein illustrate the controlbody and the cartridge in a working relationship, it is understood thatthe control body and the cartridge can exist as individual devices.Accordingly, any discussion otherwise provided herein in relation to thecomponents in combination also should be understood as applying to thecontrol body and the cartridge as individual and separate components.

In another aspect, the invention can be directed to kits that provide avariety of components as described herein. For example, a kit cancomprise a control body with one or more cartridges. A kit further cancomprise a control body with one or more charging components. A kitfurther can comprise a control body with one or more batteries. A kitfurther can comprise a control body with one or more cartridges and oneor more charging components and/or one or more batteries. In furtherembodiments, a kit can comprise a plurality of cartridges. A kit furthercan comprise a plurality of cartridges and one or more batteries and/orone or more charging components. The inventive kits further can includea case (or other packaging, carrying, or storage component) thataccommodates one or more of the further kit components. The case couldbe a reusable hard or soft container. Further, the case could be simplya box or other packaging structure.

Many modifications and other embodiments of the invention will come tomind to one skilled in the art to which this invention pertains havingthe benefit of the teachings presented in the foregoing descriptions andthe associated drawings. Therefore, it is to be understood that theinvention is not to be limited to the specific embodiments disclosedherein and that modifications and other embodiments are intended to beincluded within the scope of the appended claims. Although specificterms are employed herein, they are used in a generic and descriptivesense only and not for purposes of limitation.

The invention claimed is:
 1. A smoking article comprising: asubstantially tubular shell; an air passage through at least a portionof the shell; an aerosolization zone with a resistive heating elementsubstantially in line with the air passage; a first reservoir within theshell, the first reservoir containing a liquid aerosol precursorcomprising a polyhydric alcohol; a second reservoir within the shellseparate from the first reservoir, the second reservoir containing aliquid flavor material; a first transport element providing fluidcommunication between the first reservoir and the aerosolization zone;and a second transport element separate from the first transport elementproviding fluid communication between the second reservoir and theaerosolization zone; wherein the first transport element and the secondtransport element are formed of different materials, at least one of thefirst transport element and the second transport element is a carbonfoam, and the first transport element exhibits one or more differenttransport properties relative to the second transport element; andwherein transporting the liquid aerosol precursor comprising thepolyhydric alcohol from the first reservoir to the aerosolization zonevia a first transport element and transporting the liquid flavormaterial from the second reservoir to the aerosolization zone via thesecond transport element is normalized such that a rate of transport ofthe liquid aerosol precursor comprising the polyhydric alcohol differsfrom a rate of transport of the liquid flavor material by about 15% orless.
 2. The smoking article of claim 1, wherein the article comprises aplurality of resistive heating elements.
 3. The smoking article of claim1, wherein the article comprises a first resistive heating element and asecond resistive heating element, wherein the first transport elementprovides fluid communication between the first reservoir and the firstresistive heating element, and wherein the second transport elementprovides fluid communication between the second reservoir and the secondresistive heating element.
 4. The smoking article of claim 3, comprisinga control component adapted to operate the first resistive heatingelement by a first heating protocol and operate the second resistiveheating element by a second, different heating protocol.
 5. The smokingarticle of claim 4, wherein the article comprises an electrical powersource, and wherein the control component is adapted to controlelectrical current flow from the power source to the first resistiveheating element and the second resistive heating element such that therespective heating elements heat to different temperatures or heat fordifferent lengths of time or both heat to different temperatures andheat for different lengths of time.
 6. The smoking article of claim 1,wherein both of the first reservoir and the second reservoir comprise afibrous material that is at least partially saturated with therespective liquid.
 7. The smoking article of claim 1, wherein the firsttransport element and the second transport element are interconnected inthe aerosolization zone.
 8. A method of forming an aerosol in a smokingarticle, the method comprising: drawing air through an air passage inthe smoking article; activating a power source within the smokingarticle to cause flow of electrical current from the power source to aresistive heating element positioned within an aerosolization zone inthe smoking article; transporting a liquid aerosol precursor comprisinga polyhydric alcohol from a first reservoir to the aerosolization zonevia a first transport element; transporting a liquid flavor materialfrom a second reservoir to the aerosolization zone via a secondtransport element, wherein the first transport element and the secondtransport element are formed of different materials, and at least one ofthe first transport element and the second transport element is a carbonfoam; and heating the liquid aerosol precursor comprising the polyhydricalcohol and the liquid flavor material to form a vapor that mixes withthe air drawn through the air passage; wherein the first transportelement exhibits one or more different transport properties relative tothe second transport element; and wherein transporting the liquidaerosol precursor comprising the polyhydric alcohol from the firstreservoir to the aerosolization zone via a first transport element andtransporting the liquid flavor material from the second reservoir to theaerosolization zone via the second transport element is normalized suchthat a rate of transport of the liquid aerosol precursor comprising thepolyhydric alcohol differs from a rate of transport of the liquid flavormaterial by about 15% or less.
 9. The method of claim 8, wherein theliquid aerosol precursor comprising the polyhydric alcohol istransported at a first rate, and the liquid flavor material istransported at second, different rate.
 10. The method of claim 8,comprising transporting the liquid aerosol precursor comprising thepolyhydric alcohol from the first reservoir to the resistive heatingelement in the aerosolization zone and transporting the liquid flavormaterial from the second reservoir to a second resistive heating elementin the aerosolization zone.
 11. The method of claim 10, comprisingcontrolling the flow of electrical current from the power source to theresistive heating element and to the second resistive heating elementsuch that resistive heating element is heated by a first heatingprotocol and the second resistive heating element is heated by a second,different heating protocol.
 12. The method of claim 11, comprisingcontrolling the flow of electrical current from the power source to theresistive heating element and the second resistive heating element suchthat the respective heating elements heat to different temperatures orheat for different lengths of time or both heat to differenttemperatures and heat for different lengths of time.
 13. The smokingarticle of claim 1, wherein the first transport element and the secondtransport element exhibit different flow rates.
 14. The smoking articleof claim 1, wherein at least one of the first transport element and thesecond transport element is a sintered material.